Special trees that grow faster, fight pollution, produce better wood, and even sense chemical attacks are being planted by scientists in the US.
When 40 per cent of Hawaii's US$14 million-a-year papaya (木瓜)industry was destroyed by a virus five years ago, work began on creating genetically engineered(转基因的)trees.
Researchers successfully introduced seeds that were designed to resist the virus.Since then, more and more people have been testing genetically engineered trees.Some researchers put special bacteria into trees to help them grow faster and produce better wood.Others are trying to create trees that can clean polluted soil.Meanwhile fruit farmers are looking for trees that are strong enough to resist worms, and paper companies want trees that produce more wood and therefore more paper.
The Pentagon (五角大楼) even gave the researchers US$500,000 this year after they developed a pine tree that changes its colours if it senses a chemical attack.So far, the poplar, eucalyptus (杨树与桉树), apple and coffee trees are among those being engineered.All this can be done today because we have a better understanding of tree genomes (基因组).
However, some people fear that the genetically engineered trees will cause dangerous results.They are worried that the new trees will breed with natural species and change the balance of the forest environment.
“It could be destructive,” said Jim Diamond, an environmentalist. “Trees are what is left of our natural environment and home to many endangered species.”
But researchers insist that science could give nature a fighting chance against both natural and man-made dangers.They hope to answer the critics by stopping the new trees from breeding, so their effect on the environment can be controlled.
1.Which kind of tree is not the ones that scientists are planting in the US?
A.Trees that worms can't hurt.
B.Genetically engineered trees.
C.Trees that can resist wind better.
D.Trees that can protect themselves at a chemical attack.
2.What caused the American scientists to work on special trees?
A.Tree genomes are mapped out so scientists know how to improve trees.
B.Great numbers of trees have been lost due to attacks by viruses.
C.Researchers successfully introduced seeds designed to resist the virus.
D.They think science could give nature a fighting chance against both natural and man-made dangers.
3.Which of the following was probably the first kind of trees being engineered?
A.Papaya. B.Pine. C.Apple. D.Poplar.
4.Why did critics think engineered trees dangerous? Because ________.
A.these trees can destroy the balance of nature
B.everything except trees has been genetically engineered
C.trees are home to many endangered species
D.these trees may affect normal trees
高三英语阅读理解中等难度题
Special trees that grow faster, fight pollution, produce better wood, and even sense chemical attacks are being planted by scientists in the US.
When 40 per cent of Hawaii's US$14 million-a-year papaya (木瓜)industry was destroyed by a virus five years ago, work began on creating genetically engineered(转基因的)trees.
Researchers successfully introduced seeds that were designed to resist the virus.Since then, more and more people have been testing genetically engineered trees.Some researchers put special bacteria into trees to help them grow faster and produce better wood.Others are trying to create trees that can clean polluted soil.Meanwhile fruit farmers are looking for trees that are strong enough to resist worms, and paper companies want trees that produce more wood and therefore more paper.
The Pentagon (五角大楼) even gave the researchers US$500,000 this year after they developed a pine tree that changes its colours if it senses a chemical attack.So far, the poplar, eucalyptus (杨树与桉树), apple and coffee trees are among those being engineered.All this can be done today because we have a better understanding of tree genomes (基因组).
However, some people fear that the genetically engineered trees will cause dangerous results.They are worried that the new trees will breed with natural species and change the balance of the forest environment.
“It could be destructive,” said Jim Diamond, an environmentalist. “Trees are what is left of our natural environment and home to many endangered species.”
But researchers insist that science could give nature a fighting chance against both natural and man-made dangers.They hope to answer the critics by stopping the new trees from breeding, so their effect on the environment can be controlled.
63.Which kind of tree is not the ones that scientists are planting in the US?
A.Trees that worms can't hurt.
B.Genetically engineered trees.
C.Trees that can resist wind better.
D.Trees that can protect themselves at a chemical attack.
64.What caused the American scientists to work on special trees?
A.Tree genomes are mapped out so scientists know how to improve trees.
B.Great numbers of trees have been lost due to attacks by viruses.
C.Researchers successfully introduced seeds designed to resist the virus.
D.They think science could give nature a fighting chance against both natural and man-made dangers.
65.Which of the following was probably the first kind of trees being engineered?
A.Papaya. B.Pine. C.Apple. D.Poplar.
66.Why did critics think engineered trees dangerous? Because ________.
A.these trees can destroy the balance of nature
B.everything except trees has been genetically engineered
C.trees are home to many endangered species
D.these trees may affect normal trees
高三英语阅读理解简单题查看答案及解析
Special trees that grow faster, fight pollution, produce better wood, and even sense chemical attacks are being planted by scientists in the US.
When 40 per cent of Hawaii's US$14 million-a-year papaya (木瓜)industry was destroyed by a virus five years ago, work began on creating genetically engineered(转基因的)trees.
Researchers successfully introduced seeds that were designed to resist the virus.Since then, more and more people have been testing genetically engineered trees.Some researchers put special bacteria into trees to help them grow faster and produce better wood.Others are trying to create trees that can clean polluted soil.Meanwhile fruit farmers are looking for trees that are strong enough to resist worms, and paper companies want trees that produce more wood and therefore more paper.
The Pentagon (五角大楼) even gave the researchers US$500,000 this year after they developed a pine tree that changes its colours if it senses a chemical attack.So far, the poplar, eucalyptus (杨树与桉树), apple and coffee trees are among those being engineered.All this can be done today because we have a better understanding of tree genomes (基因组).
However, some people fear that the genetically engineered trees will cause dangerous results.They are worried that the new trees will breed with natural species and change the balance of the forest environment.
“It could be destructive,” said Jim Diamond, an environmentalist. “Trees are what is left of our natural environment and home to many endangered species.”
But researchers insist that science could give nature a fighting chance against both natural and man-made dangers.They hope to answer the critics by stopping the new trees from breeding, so their effect on the environment can be controlled.
1.Which kind of tree is not the ones that scientists are planting in the US?
A.Trees that worms can't hurt.
B.Genetically engineered trees.
C.Trees that can resist wind better.
D.Trees that can protect themselves at a chemical attack.
2.What caused the American scientists to work on special trees?
A.Tree genomes are mapped out so scientists know how to improve trees.
B.Great numbers of trees have been lost due to attacks by viruses.
C.Researchers successfully introduced seeds designed to resist the virus.
D.They think science could give nature a fighting chance against both natural and man-made dangers.
3.Which of the following was probably the first kind of trees being engineered?
A.Papaya. B.Pine. C.Apple. D.Poplar.
4.Why did critics think engineered trees dangerous? Because ________.
A.these trees can destroy the balance of nature
B.everything except trees has been genetically engineered
C.trees are home to many endangered species
D.these trees may affect normal trees
高三英语阅读理解中等难度题查看答案及解析
Special trees that grow faster, fight pollution, produce better wood, and even sense chemical attacks are being planted by scientists in the US.
When 40 per cent of Hawaii's US$14 million-a-year papaya (木瓜)industry was destroyed by a virus five years ago, work began on creating genetically engineered(转基因的)trees.
Researchers successfully introduced seeds that were designed to resist the virus.Since then, more and more people have been testing genetically engineered trees.Some researchers put special bacteria into trees to help them grow faster and produce better wood.Others are trying to create trees that can clean polluted soil.Meanwhile fruit farmers are looking for trees that are strong enough to resist worms, and paper companies want trees that produce more wood and therefore more paper.
The Pentagon (五角大楼) even gave the researchers US$500,000 this year after they developed a pine tree that changes its colours if it senses a chemical attack.So far, the poplar, eucalyptus (杨树与桉树), apple and coffee trees are among those being engineered.All this can be done today because we have a better understanding of tree genomes (基因组).
However, some people fear that the genetically engineered trees will cause dangerous results.They are worried that the new trees will breed with natural species and change the balance of the forest environment.
“It could be destructive,” said Jim Diamond, an environmentalist. “Trees are what is left of our natural environment and home to many endangered species.”
But researchers insist that science could give nature a fighting chance against both natural and man-made dangers.They hope to answer the critics by stopping the new trees from breeding, so their effect on the environment can be controlled.
1.Which kind of tree is not the ones that scientists are planting in the US?
A.Trees that worms can't hurt.
B.Genetically engineered trees.
C.Trees that can resist wind better.
D.Trees that can protect themselves at a chemical attack.
2.What caused the American scientists to work on special trees?
A.Tree genomes are mapped out so scientists know how to improve trees.
B.Great numbers of trees have been lost due to attacks by viruses.
C.Researchers successfully introduced seeds designed to resist the virus.
D.They think science could give nature a fighting chance against both natural and man-made dangers.
3.Which of the following was probably the first kind of trees being engineered?
A.Papaya. B.Pine. C.Apple. D.Poplar.
4.Why did critics think engineered trees dangerous? Because ________.
A.these trees can destroy the balance of nature
B.everything except trees has been genetically engineered
C.trees are home to many endangered species
D.these trees may affect normal trees
高三英语阅读理解中等难度题查看答案及解析
City trees grow faster and die younger than trees in rural forestry, a new study finds. Over their lifetimes,then, urban trees will likely absorb less CO2 from the air thah forest trees.
As we all know, the earth would be freezing or burning hot without C02. However, CO2 is a greenhouse gas, meaning it traps energy from the sun as/heat. That makes temperatures near the ground rise. Human activities, especially the widespread burning-of fossil(化石)fuels,have been sending extra greenhouse gases into the air. This has led to a rise in average temperatures across the globe.
Studies had shown forests readily absorb C02,but there hadn’t been much data on whether city trees grow, die and absorb CO2 at the same rate as forest trees do. So some researchers decided to find out.
To figure out how quickly trees were growing, researchers tracked their diameters (the width of their trunks) between 2005 and 2014. A tree’s diameter increases as it grows, just as a person’s waist size increases as they gain weight. About half the weight of a tree is carbon, research has shown. Most of the rest is water. Over the nine years’ tracking, the researchers found city trees absorbed four times as much carbon from the air as forest trees. However, they were twice as likely to die. So over the lifetime of each type of tree, forest trees actually absorbed more C02.
City trees grew faster because they had less competition for light from their neighbors. In a forest,trees tend to grow close together,shading their neighbors. Street trees also benefit from higher levels of nitrogen (氮)in rainwater. Nitrogen helps plants grow. Waste gases from gas-burning cars also contain nitrogen, thus enriching city air with nitrogen. Later, rainwater may wash much of it to the ground. Some street trees may also have better access to water than trees in the country because the underground water pipes can leak.
1.What can he known about CO2 from paragraph 2?
A.It is one of the side effects of greenhouses.
B.It greatly accelerates the process of global warming.
C.It results from the widespread burning of fossil fuels.
D.It prevents the earth from becoming unsuitable to live on.
2.Why did researchers track the diameters of trees?
A.To know about their growth rates.
B.To find out how much they weigh.
C.To check whether they were healthy.
D.To assess the carbon amounts in them.
3.What advantage do city trees have over forest trees?
A.They are more likely to access growth promoters.
B.They can enjoy more water coming from the air.
C.They can enjoy more shade from neighbors.
D.They are better at competing for light.
4.What will probably be talked about if the passage is continued?
A.How urban trees can live longer.
B.Why city living makes trees die young.
C.How trees respond to dry soil conditions.
D.Why faster-growing trees absorb more C02.
高三英语阅读理解困难题查看答案及解析
Myth: If you cut your hair, it will grow long faster.
Truth: That’s not true. “Your hair isn’t like a lawn or a rosebush, where cutting can stimulate fresh growth,” says Phillip Kingsley. The length of your hair is genetically determined. When it reaches a certain length, it stops growing. When you clear up the dead split ends, this make your hair look healthier, but not necessarily longer.
Myth: If you skip meals, you lose weight fast.
Truth: There’s no truth in this advice. Not only will you lose weight by starving yourself, but according to Carol Ann Rinzler, this may actually cause you to gain weight. Rinzler reasons that missing a meal causes your metabolism(新陈代谢) to slow down so that you burn food more slowly. This only makes you feel hungrier and by the time you finally do reach the table you will probably eat more food. Strange as it may seem, studies show that eating several small meals and snacks throughout the day is a more healthy way to lose pounds.
Myth: If you swallow gum,it will stay inside your stomach for seven years.
Truth: Actually, it takes just a few days for gum to make its exit---not seven years, says NeiIzenberg, M. D., editor of Kids Health Organization. But because gum is made of the same thing as rubber, it cannot be fully digested in your stomach--- so if you gum up the works on a regular basis, you might find yourself in a sticky situation.
Myth: The best way to stop a nosebleed is to lift your head back.
Truth: Now that’s bad advice. Bloody noses are caused by broken blood vessels, so while lifting your head back might stop the fluid from rushing out of your nose, it won’t stop the bleeding; you’ll just end up swallowing lots of blood. Your best bet? “Rest quietly. Don’t poke or pick, and the blood will naturally clot (凝结) within a minute or two”. Suggests Dr. Izenberg.
1.The length of your hair is determined by ________
A. cutting it often B. your gene
C. the food you eat D. clearing up the dead split ends
2.According to Carol Ann Rinzler, skipping meals will __________.
A. help you lose weight fast
B. help you lose weight slowly
C. cause you to become fatter
D. make you burning food more quickly
3.Which of the following statements is NOT true according to the passage?
A. Gum cannot be fully digested in the stomach
B. Gum can stay inside your stomach for seven years if you swallow it
C. Gum can leave your stomach after you swallow in a few days later
D. If you often swallow gum, you might find yourself in a sticky situation
高三英语阅读理解中等难度题查看答案及解析
Myth: If you cut your hair, it will grow long faster.
Truth: That’s not true. “Your hair isn’t like a lawn or a rosebush, where cutting can stimulate fresh growth,” says Phillip Kingsley. The length of your hair is genetically determined. When it reaches a certain length, it stops growing. When you clear up the dead split ends, this make your hair look healthier, but not necessarily longer.
Myth: If you skip meals, you lose weight fast.
Truth: There’s no truth in this advice. Not only will you not lose weight by starving yourself, but according to Carol Ann Rinzler, this may actually cause you to gain weight. Rinzler reasons that missing a meal causes your metabolism(新陈代谢) to slow down so that you burn food more slowly. This only makes you feel hungrier and by the time you finally do reach the table you will probably eat more food. Strange as it may seem, studies show that eating several small meals and snacks throughout the day is a more healthy way to lose pounds.
Myth: If you swallow gum,it will stay inside your stomach for seven years.
Truth: Actually, it takes just a few days for gum to make its exit---not seven years, says NeiIzenberg, M. D., editor of Kids Health Organization. But because gum is made of the same thing as rubber, it cannot be fully digested in your stomach--- so if you gum up the works on a regular basis, you might find yourself in a sticky situation.
Myth: The best way to stop a nosebleed is to lift your head back.
Truth: Now that’s bad advice. Bloody noses are caused by broken blood vessels, so while lifting your head back might stop the fluid from rushing out of your nose, it won’t stop the bleeding; you’ll just end up swallowing lots of blood. Your best bet “Rest quietly. Don’t poke or pick, and the blood will naturally clot (凝结成块) within a minute or two”, suggests Dr. Izenberg.
1.The length of your hair is determined by ________.
A. cutting it often
B. your gene
C. the food you eat
D. clearing up the dead split ends.
2.According to Carol Ann Rinzler, skipping meals will __________.
A. help you lose weight fast
B. help you lose weight slowly
C. cause you to become fatter
D. make you burning food more quickly
3. Which of the following statements is NOT true according to the passage?
A. Gum cannot be fully digested in the stomach.
B. Gum can stay inside your stomach for seven years if you swallow it.
C. Gum can leave your stomach after you swallow in a few days later.
D. If you often swallow gum, you might find yourself in a sticky situation
高三英语阅读理解困难题查看答案及解析
Pollution is a growing problem that is facing the international community, but even the actions that we take can make a difference. Littering is creating environmental problems all over the world and is often created by careless individuals. If we guard our actions against careless littering we can ensure a better world for everyone.
Littering is a severe problem in many countries around the world. For example, the African city of Kampala, the capitol of Uganda, is suffering from the consequences of littering. For many years the city’s poor didn’t have a proper way to dispose of trash, so garbage filled the streets. Over the years much of the plastic garbage would slowly be pushed into the ground. This plastic litter doesn’t allow rain water to seep into the ground and has caused flooding. In many of Kampala’s poor neighborhoods whenever it rains people’s homes become flooded with water. This water is often dirty and has allowed diseases to spread. This flooding has become so bad that the Ugandan government has banned plastic bags in the entire country to stop the littering.
Trash often finds its way into the water. Today the world’s oceans are believed to have millions of tons of trash floating around in them. This creates a problem for wildlife because they may accidentally eat the trash and die from it. Scientists have found on very remote islands baby birds that have died because their stomachs were full of trash. Fish often get tangled in plastic and will also die. Our actions in our own countries affect the most remote parts of the planet.
We can all be part of the solution to stop this pollution, just by preventing careless littering. If you need to throw something away, don’t toss it over your shoulder — find a trash can. If you see a friend littering tell them not to. By making this small change we can create a better world for all.
1.What does the author say is the cause of littering? (No more than 4 words)
________________________________________________________________________
2.How does trash cause flooding? (No more than 10 words)
_______________________________________________________________________
3.How can local actions affect the international environment? (No more than 12 words)
________________________________________________________________________
4.What does the author suggest to prevent littering? (No more than 7 words)
________________________________________________________________________
高三英语其他题中等难度题查看答案及解析
Some trees can survive a long time without watering. Think of trees that grow in the desert. But other trees may need more moisture(水分)than they can get from rainfall or from the air.
The soil stores moisture during cooler weather. But most of that moisture is gone by the middle or rend of the hottest months of the year. Trees and other plants can look thirsty. Leaves can become droopy(下垂的)and hang downward. They can also turn yellow. Yellowing can be a sign of too much water. But it can also be a warning sign of too little water.
With a newly planted tree, the roots not yet spread out from the root ball. The root ball can become dry faster than the dirt around it. So put water on the area of the root ball and the surrounding soil until the roots become established.
Once a tree is well established, water deeply instead of often. The amount of water needed depends on the tree and the soil. Clay soils hold water for longer periods while sandy soils hold less water. During the hottest season, a deep watering may satisfy a tree for anywhere from ten days to four weeks. While watering , we should have a stop, for the soil needs a little time to absorb the water. Otherwise the water runs off the surface and gets wasted. Avoid watering established trees at the base of trunk. This can harm the tree. Too much water in the soil at the base of a tree can lead to the growth of fungi(霉菌). If the area is too wet, harmful organisms have a better chance to invade the tree and cause disease, which is true especially in Mediterranean and semi-dry climates. Many trees in these climates have adapted to having a dry area near their base during the hottest season.
1.What’s the author’s purpose of mentioning desert trees in the first paragraph?
A. To tell the truth that there is life in the desert
B. To prove trees can get water in a natural way
C. To explain how trees collect and store rainfall
D. To show how trees absorb moisture from the air
2.Why shouldn’t an established tree be watered at the base of its trunk?
A. To speed up the absorption of water
B. To reduce the amount of water needed
C. To enable the soil to hold water longer
D. To make it less likely to catch diseases
3.According to the passage, which of the following is TRUE?
A. Most moisture stored by the soil is kept even after hot months
B. Newly planted trees should be watered more deeply than often
C. Trees don’t necessarily lack water when their leaves turn yellow
D. Different soils’ water-holding abilities are more or less the same
4.What is the main idea of the passage?
A. How can trees survive without watering? B. What makes leaves yellow?
C. How can we water trees? D. What will harm trees?
高三英语阅读理解中等难度题查看答案及解析
When you long for life without difficulties, _____ yourselves that trees grow strong in contrary winds and diamonds are made under pressure.
A.to remind B.remind C.reminding D.reminded
高三英语单项填空中等难度题查看答案及解析
Colorado’s Grays Peak(格雷斯峰)rises 14,278 feet above sea level, high enough that trees can’t grow toward the top. It was in this difficult environment that Cindy was _________ enough to injure her left knee.
It was August 2018, and Cindy, 56, was on her way back down the trail(小路)with three friends. As a storm was coming, they were_____ to get off the mountain. When they_______ a rocky drop of a couple of feet, Cindy________ that instead of moving down slowly — the safe way to go — she would____. She landed on her left leg. Then she felt a sharp___ in her leg.
Every_________ after that was extremely painful. Before long, she had to_________ . As one friend ran down to get_______ , a number of other hikers, all strangers,_______ to help Cindy down the narrow trail by walking on either side of her to support her _______, but that proved slow and dangerous.
Finally, one hiker, Matt, asked her,“How do you feel about a fireman’s _______?”Before she knew it, he had___ her over his shoulder.“Now, I’m not tiny,”says Cindy, a former college basketball star.______ Matt couldn’t carry her all the way down by himself. So six hikers and one of her friends______ carrying her. Three hours and two rock⁃strewn miles later, this human conveyor belt______ the medical workers in the end, who_______ Cindy to the nearby hospital.
Now she has mostly _________ from her unlucky hike, but Cindy knows she’ll never shake one thing from that day: the_______ of the band of strangers who came to her_______ .“I’m still moved to tears.”
1.A.uncertain B.strange C.surprised D.unfortunate
2.A.serious B.anxious C.afraid D.normal
3.A.cleared B.visited C.missed D.approached
4.A.decided B.noticed C.complained D.reminded
5.A.return B.arrive C.jump D.wait
6.A.pain B.drop C.shock D.relief
7.A.goal B.step C.choice D.stage
8.A.leave B.continue C.follow D.stop
9.A.money B.advice C.help D.courage
10.A.happened B.attempted C.refused D.hesitated
11.A.weight B.family C.opinion D.equipment
12.A.carry B.image C.career D.style
13.A.touched B.seized C.threw D.lifted
14.A.Bravely B.Naturally C.Clearly D.Gradually
15.A.put off B.took turns C.burst out D.felt like
16.A.met B.recognized C.ordered D.escaped
17.A.introduced B.allowed C.invited D.rushed
18.A.travelled B.recovered C.regretted D.suffered
19.A.experience B.practice C.memory D.excitement
20.A.contact B.senses C.rescue D.terms
高三英语完形填空中等难度题查看答案及解析