All plant cells are capable of taking up(吸收)water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger.
In common land plants, the living cells of roots take upmost of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.
Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度).
In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies.
In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.
1.Wood becomes larger because of ________.
A.dead cell walls B.water entering dead cells
C.the growth of cells D.the death of cells
2.From the passage we know that the evolutionary scale is graded according to________.
A.evolutionary cycles B.heights and depths
C.time D.kinds
3.The “bromeliad” is a plant that________.
A.has no roots B.is a pineapple
C.can grow anywhere D.takes up water through its leaves
4.The most suitable title for this passage is “________”.
A.Absorption of water by plants B.Rootless plants in America
C.Plants in the desert D.Higher plants
高三英语阅读理解中等难度题
All plant cells are capable of taking up(吸收)water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger.
In common land plants, the living cells of roots take upmost of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.
Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度).
In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies.
In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.
1.Wood becomes larger because of ________.
A.dead cell walls B.water entering dead cells
C.the growth of cells D.the death of cells
2.From the passage we know that the evolutionary scale is graded according to________.
A.evolutionary cycles B.heights and depths
C.time D.kinds
3.The “bromeliad” is a plant that________.
A.has no roots B.is a pineapple
C.can grow anywhere D.takes up water through its leaves
4.The most suitable title for this passage is “________”.
A.Absorption of water by plants B.Rootless plants in America
C.Plants in the desert D.Higher plants
高三英语阅读理解中等难度题查看答案及解析
– These plants ______ lack of water.
--- You should have watered them.
A.died for | B.dead for | C.was killed | D.died |
高三英语单项填空中等难度题查看答案及解析
Although it has been revealed in recent years that plants are capable of seeing, hearing and smelling, they are still usually thought of as silent. But now, for the first time, they have been recorded making ultrasonic cries when stressed, which researchers say could open up a new field of precision agriculture where farmers listen for water-starved crops.
Itzhak Khait and his colleagues at Tel Aviv University in Israel found that tomato and tobacco plants made cries at frequencies humans cannot hear when stressed by a lack of water or when their stem is cut.
Microphones placed 10 centimetres from the plants picked up sounds in the ultrasonic range of 20 to 100 kilohertz, which the team says insects and some mammals would be capable of hearing and responding to from as far as 5 metres away. A moth may decide against laying eggs on a plant that sounds water-stressed, the researchers suggest. Plants could even hear that other plants are short of water and react accordingly, they speculate.
On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15. Unstressed plants produced fewer than one sound per hour, on average.
It is even possible to distinguish between the sounds to know what the stress is. The researchers trained a machine-learning model to discriminate between the plants’ sounds and the wind, rain and other noises of the greenhouse, correctly identifying in most cases whether the stress was caused by dryness or a cut, based on the sound’s intensity and frequency. Water-hungry tobacco appears to make louder sounds than cut tobacco, for example.
Enabling farmers to listen for water-stressed plants could “open a new direction in the field of precision agriculture”, the researchers suggest. They add that such an ability will be increasingly important as climate change exposes more areas to drought.
“The suggestion that the sounds that drought-stressed plants make could be used in precision agriculture seems feasible if it is not too costly to set up the recording in a field situation,” says Anne Visscher at the Royal Botanic Gardens, Kew, in the UK.
She warns that the results can’t yet be broadened out to other stresses, such as salt or temperature, because these may not lead to sounds. In addition, there have been no experiments to show whether moths or any other animal can hear and respond to the sounds the plants make, so that idea remains speculative(推测的)for now, she says.
1.The experiment by researchers at Tel Aviv University shows that_______.
A.tobacco plants make louder sounds than tomato plants when hurt
B.water-hungry tomato plants are more sensible than tobacco plants
C.unstressed plants produced sounds of laughter when being watered
D.plants respond to the sounds the plants make and protect themselves
2.What is Anne Visscher’s attitude towards the finding of the experiment?
A.Appreciative B.Doubtful
C.Cautious D.Optimistic
3.It can be learnt from the research that ________.
A.greenhouse effects can be avoided
B.soil condition can be adjusted in time.
C.plant condition can be diagnosed faster.
D.insects can be detected and removed easily.
4.What is the best title for the article?
A.Plants Get Stressed Just Like Us
B.Plants Scream in Presence of Stress
C.Sounds of Plants Detected Far Away
D.Sounds of Plants Break Farmers’ Hearts
高三英语阅读理解中等难度题查看答案及解析
Most students are for the new school rule, which says all the students not take their cell phones into the classroom.
A. will B. can C. shall D. must
高三英语单项填空中等难度题查看答案及解析
Scientists are working to develop crop plants that can reduce the amount of water used for agriculture. Almost sixty percent of the world’s freshwater withdrawals from rivers, lakes and other water resources go toward irrigating fields.
Scientists are using biotechnology as well as traditional breeding methods to develop water-saving crops to feed a growing world.
Thomas “Tommy” Carter is a plant scientist in North Carolina. He works for the Agricultural Research Service in the United States Department of Agriculture. He leads Team Drought, a group of researchers at five universities. They have been using conventional breeding methods to develop and test soybeans that can grow well under dry conditions.
Tommy Carter started working on drought-resistant soybeans in 1981. His research has taken him as far as China, where soybeans have been grown for thousands of years.
Farmers in the United States, however, have grown soybeans for only about a century. Tommy Carter says the soybeans they grow are for the most part genetically similar. More differences could better protect crops against climate changes that can reduce production. Those changes include water shortages which could increase from global warming.
The Agriculture Department has a soybean germplasm(胚质) collection, a collection of genetic material passed from one generation to the next. Members of Team Drought studied more than 2,500 examples from the collection.
They looked at ones from the home of soybeans, Asia. They searched for germplasms that could keep plants from weakening and wilting (凋谢)during hot, dry summers in the United States.
Tommy Carter says they found only five. But these slow-wilting lines, he says, produce four to eight bushels(英斗)more than normal soybeans under drought conditions. The yield depends on location and environment.
Scientists are also working on other plants that either use less water or use it better, or both. For example, companies like Monsanto, DuPont and Syngenta have been developing corn with reduced water needs. Monsanto expects to be ready in a few years to market its first corn seeds genetically engineered to resist drought.
1.According to the passage, scientists try to find out how to _______.
A. grow crops with less water
B. increase crop production
C. feed a growing world
D. save the world’s water resource
2.Why did Tommy Carter come to China?
A. He likes traveling.
B. China has a long history.
C. He’s doing research into soybeans.
D. He works for the Agricultural Research Service.
3.What’s inferred from the passage?
A. Climate changes lead to global warming.
B. Water shortages contribute to global warming.
C. Genetically different soybeans need much water to grow.
D. Genetically different soybeans help to fight against damaging climate changes.
4.What do we know about slow-wilting plants talked about in the passage?
A. They yield big profits.
B. They can grow in almost any climate.
C. They seem to be drought-resistant.
D. They need much water for their growth.
高三英语阅读理解中等难度题查看答案及解析
The plant is dead. I _____ it more water.
A. will give B. would have given C. must give D. should have give
高三英语单项填空中等难度题查看答案及解析
The remains of animals and plants which ________ in or near water are most likely to be preserved.
A.had lived B.lived C.live D.are living
高三英语单项填空中等难度题查看答案及解析
Late blight (晚疫病) is a common disease of plants such as tomatoes and potatoes, capable of wiping out entire crops on commercial-sized fields. If conditions are favorable, it can quickly spread to other plants through wet soil and wind.
In history, late blight caused over 1 million deaths in Ireland. Today it still causes more than 6.7 billion dollars in annual losses worldwide. Small farms and growers are often the hardest hit, many stating losing almost two-thirds of their yearly production, because usually they don’t have money to identify and treat the disease.
But farmers may have a new weapon now. The technology, designed by researchers at North Carolina State University can recognize sick plants early by employing a piece of test paper that plugs into (接入) a reader on a smartphone.
Plants produce signaling chemicals from their leaves. “If a plant is diseased, the type and concentration of these chemicals changes,” said Wei Qingshan, an engineer at North Carolina State University. If the farmer suspects a late blight infection is underway, he can remove a leaf from a living plant and place it in a small, covered glass jar. After the leaf’s volatile (挥发性的) chemicals have accumulated for 15 minutes or so, the cap is removed and the air is pumped from the jar into a reader attached to the back of a smartphone. Inside the smartphone reader is a piece of paper specially treated with dyes (染料) by the researchers. Upon interacting (相互作用) with the plant’s volatile chemicals, the paper changes color to indicate the presence or absence of the late blight.
The researchers hope to tailor the technology for other crop diseases, which continue to appear as climate change and global trade increase the stress on agricultural systems. “This is an important step in the improvement of global food security,” Wei Qingshan said.
1.What are the statistics in Paragraph 2 mainly about?
A.The damage caused by late blight.
B.The money put into late blight treatment.
C.The number of crops in a commercial-sized field.
D.The yearly production of small farms and growers.
2.According to Wei Qingshan, how would a farmer find out if a plant was infected?
A.By treating the plant with special dyes.
B.By putting volatile chemicals on the plant.
C.By testing the air in the jar with a leaf inside.
D.By examining the land with a smartphone reader.
3.What do the researchers expect of their new technology?
A.It’ll reach farmers soon.
B.It’ll get rid of late blight.
C.It’ll be beneficial to the climate.
D.It’ll be able to detect more crop diseases.
4.What is the purpose of this passage?
A.To introduce a test method of late blight.
B.To explain the causes of late blight.
C.To discuss the effects of late blight.
D.To tell the history of late blight.
高三英语阅读理解中等难度题查看答案及解析
Drinking water , having a healthy snack and taking exercise are all positive ways to ____you when you are working on a tight schedule.
A. relieve B. refresh C. liberate D. comfort
高三英语单项填空中等难度题查看答案及解析
Drinking water, having a healthy diet and taking exercise are all positive ways to ________ you when you are working on a tight schedule.
A.relieve B.refresh
C.liberate D.comfort
高三英语单项填空简单题查看答案及解析