Dodder is an unusual and unwanted plant that attacks other plants. Except for its flowers, the plant looks like spaghetti, a kind of noodles in the shape of long thin pieces that look like string when they are cooked. Its almost leafless, thread-like stems (茎) hang down on top of other plants that dodder needs to stay alive. Dodder does not produce its own food. Instead, it steals food from other plants. It feeds by sucking juices from the plant which is wrapped around, often making its host very weak or even killing it.
Dodder can find other plants by their smell. When a young dodder plant starts growing, it follows the smell of plants it prefers, like tomato plants, potato plants, or other farm crops. Unlike most plants that usually grow in the direction of light or warmth, a dodder plant will grow in the direction of, for example, tomato smell—if a tomato happens to be growing nearby.
However, a young dodder plant must find a host plant quickly. It no longer needs its root once it is attached to the host and wrapped around it. If it cannot catch a smell of a potential host within a few days, it will dry up and disappear—even if there is plenty of water around. Once it finds a host, the young dodder plant will attach itself to it and start growing faster. At that point the dodder plant will drop its root.
Dodder is thus a difficult weed to manage and a real headache for farmers. When it does get out of hand, dodder can greatly reduce a farmer’s harvest or even destroy crops completely. Before sowing their produce, especially farmers in warm parts of the world often check to make sure no unwanted dodder seeds have mixed with their crop seeds. This is a good way to stop dodder plants from making their way to a crop field secretly.
1.Why does the author mention spaghetti in the first paragraph?
A. To analyze the content of some food.
B. To describe the shape of dodder plants.
C. To explain where the dodder plants come from.
D. To argue that dodder plants can be used.
2.What will happen if a dodder plant starts growing where there are no other plants around?
A. It will die sooner or later.
B. It will grow deep roots.
C. It will attract other plants.
D. It will cover the entire area of soil.
3.What can be inferred from the passage?
A. Dodder does not produce its own food.
B. Dodder can affect farmers’ income.
C. Dodder can only survive in the shade.
D. Dodder only grows in the warm areas.
4.What is the main topic of the passage?
A. A new variety of farm crops.
B. Plants that are harmful to humans.
C. The special abilities of a dangerous plant.
D. Recent improvements in farming methods.
高三英语阅读理解中等难度题
Dodder is an unusual and unwanted plant that attacked other plants. Except for its flower, the plant looks like spaghetti, a kind of noodles in the shape of long thin pieces that look like string when they are cooked. Its almost leafless, thread-like stems hang down on top of other plants that dodder needs to stay alive. Dodder does not produce its own food. Instead, it steals food from other plants. It feeds by sucking juices from the plant which is wrapped around, often making its host very weak or even killing it.
Dodder can find other plants by their smell. When a young dodder plant starts growing, it follows the smell of plants it prefers, like tomato plants, potato plants, or other farm crops. Unlike most plants that usually grow in the direction of light or warmth, a dodder plant will grow in the direction of , for example, tomato smell-if a tomato happens to be growing nearby.
However, a young dodder plant must find a host plant quickly. It no longer needs its root once it is attached to the host and wrapped around it. If it cannot catch a smell of potential host within a few days, it will dry up and vanish even if there is plenty of water around. Once it finds a host, the young dodder plant will attach itself to it and start growing faster. At that point the dodder plant will drop its root.
Dodder is thus a difficult weed to manage and a real headache for farmers. When it does get out of hand, dodder can greatly reduce a farmer’s harvest or even destroy crops completely. Before sowing their produce, especially farmers in warm parts of the world often check to make sure no unwanted dodder seeds have mixed with their crop seeds. This is a good way to stop dodder plants from making their way to a crop field secretly.
1.Why does the author mention spaghetti in the first paragraph?
A. To analyze the content of some food. B. To introduce the topic of this passage.
C. To tell the usage of the dodder plants. D. To describe the shape of dodder plants.
2.What does the underlined word “vanish” in the third paragraph mean?
A. invade B. grow
C. escape D. disappear
3.What can be inferred from the passage?
A. Dodder doesn’t produce its own food. B. Dodder gives off smell to attract plants.
C. Dodder can affect farmer’s income. D. Dodder can only survive in the shade.
4.What is the purpose of the passage?
A. To introduce a new variety of farm crops.
B. To introduce plants that are harmful to humans.
C. To introduce the special abilities of a dangerous plant.
D. To introduce recent improvements in farming methods.
高三英语阅读理解中等难度题查看答案及解析
Dodder is an unusual and unwanted plant that attacks other plants. Except for its flowers, the plant looks like spaghetti, a kind of noodles in the shape of long thin pieces that look like string when they are cooked. Its almost leafless, thread-like stems (茎) hang down on top of other plants that dodder needs to stay alive. Dodder does not produce its own food. Instead, it steals food from other plants. It feeds by sucking juices from the plant which is wrapped around, often making its host very weak or even killing it.
Dodder can find other plants by their smell. When a young dodder plant starts growing, it follows the smell of plants it prefers, like tomato plants, potato plants, or other farm crops. Unlike most plants that usually grow in the direction of light or warmth, a dodder plant will grow in the direction of, for example, tomato smell—if a tomato happens to be growing nearby.
However, a young dodder plant must find a host plant quickly. It no longer needs its root once it is attached to the host and wrapped around it. If it cannot catch a smell of a potential host within a few days, it will dry up and disappear—even if there is plenty of water around. Once it finds a host, the young dodder plant will attach itself to it and start growing faster. At that point the dodder plant will drop its root.
Dodder is thus a difficult weed to manage and a real headache for farmers. When it does get out of hand, dodder can greatly reduce a farmer’s harvest or even destroy crops completely. Before sowing their produce, especially farmers in warm parts of the world often check to make sure no unwanted dodder seeds have mixed with their crop seeds. This is a good way to stop dodder plants from making their way to a crop field secretly.
1.Why does the author mention spaghetti in the first paragraph?
A. To analyze the content of some food.
B. To describe the shape of dodder plants.
C. To explain where the dodder plants come from.
D. To argue that dodder plants can be used.
2.What will happen if a dodder plant starts growing where there are no other plants around?
A. It will die sooner or later.
B. It will grow deep roots.
C. It will attract other plants.
D. It will cover the entire area of soil.
3.What can be inferred from the passage?
A. Dodder does not produce its own food.
B. Dodder can affect farmers’ income.
C. Dodder can only survive in the shade.
D. Dodder only grows in the warm areas.
4.What is the main topic of the passage?
A. A new variety of farm crops.
B. Plants that are harmful to humans.
C. The special abilities of a dangerous plant.
D. Recent improvements in farming methods.
高三英语阅读理解中等难度题查看答案及解析
Animals can move from place to place, but plants cannot. When an animal is under attack, it can run away or fight back.. Plants certainly cannot run away, and they lack teeth and claws. But plants can defend themselves by using both physical and chemical means.
Some plants have their own ways to keep animals away. For example, the leaves of the holly plant have sharp spines (刺) that discourage grass-eating animals. Holly leaves on lower branches have more spines than leaves on upper branches. This is because the lower leaves are easier for most animals to reach..
Some plants, such as the oak tree, have thick and hard leaves that are difficult for animals to eat. Some grasses may contain a sandy material; eating such grasses wears down the animal's teeth.
Many plants also have chemical defenses. Some plants produce chemicals that taste bitter or cause an unpleasant reaction. Some plants may fight against an attack by increasing the production of these chemicals. When a caterpillar (毛虫) bites a tobacco leaf, the leaf produces a chemical messenger. This messenger sends to the roots the information to produce more nicotine. The higher levels of nicotine discourage the caterpillar.
Many plants depend on both physical and chemical defenses. A certain plant in China, for instance, has prickly (多刺的) leaves, and each prickle contains poisonous venom (毒液) A single experience with this kind of plant will teach an animal to stay away from it in the future.
1.The holly plant has more spines on the lower leaves because most animals________.
A. are not tall enough B. like the lower leaves only
C. are not clever enough D. can get the lower leaves easily
2.To defend themselves, oak trees use________.
A. chemical means B. physical means
C. bitter chemicals D. sandy materials
3.How does tobacco protect itself against an attack from a caterpillar?
A. Its leaves fight against the attack by physical means.
B. Its roots send a messenger to discourage the caterpillar.
C. Its roots increase the production of nicotine when it is attacked.
D. Its leaves produce poisonous sand to drive the caterpillar away.
4.What would be the best title for this passage?
A. Plants and Animals B. How Plants Defend Themselves
C. Attacks and Defenses D. How Animals Eat Plant Leaves
高三英语阅读理解中等难度题查看答案及解析
Animals can move from place to place, but plants cannot. When an animal is under attack, it can run away or fight back. Plants certainly cannot run away, and they lack teeth and claws. But plants can defend themselves by using both physical and chemical means.
Some plants have their own ways to keep animals away. For example, the leaves of the holly plant have sharp spines (刺) that discourage grass-eating animals. Holly leaves on lower branches have more spines than leaves on upper branches. This is because the lower leaves are easier for most animals to reach.
Some plants, such as the oak tree, have thick and hard leaves that are difficult for animals to eat. Some grasses may contain a sandy material; eating such grasses wears down the animal's teeth.
Many plants also have chemical defenses. Some plants produce chemicals that taste bitter or cause an unpleasant reaction. Some plants may fight against an attack by increasing the production of these chemicals. When a caterpillar (毛虫) bites a tobacco leaf, the leaf produces a chemical messenger. This messenger sends to the roots the information to produce more nicotine. The higher levels of nicotine discourage the caterpillar.
Many plants depend on both physical and chemical defenses. A certain plant in China, for instance, has prickly (多刺的) leaves, and each prickle contains poisonous venom (毒液). A single experience with this kind of plant will teach an animal to stay away from it in the future.
1.The holly plant has more spines on the lower leaves because most animals________.
A．are not tall enough B．like the lower leaves only
C．are not clever enough D．can get the lower leaves easily
2.To defend themselves, oak trees use________.
A．chemical means B．physical means
C．bitter chemicals D．sandy materials
3.How does tobacco protect itself against an attack from a caterpillar?
A．Its leaves fight against the attack by physical means.
B．Its roots send a messenger to discourage the caterpillar.
C．Its roots increase the production of nicotine when it is attacked.
D．Its leaves produce poisonous sand to drive the caterpillar away.
4.What would be the best title for this passage?
A．Plants and Animals B．How Plants Defend Themselves
C．Attacks and Defenses D．How Animals Eat Plant Leaves
高三英语阅读理解中等难度题查看答案及解析
It is ______ work of art that the museum has decided to buy and keep it .
A such an unusual B a so unusual C such unusual D so unusual
高三英语单项填空简单题查看答案及解析
Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures（核心体温）in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity（湿度）.
In very cold climates, there is a constant danger of developing hypothermia（低体温）, which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0°C. However, differences in persons and even the time of day can cause it to be as much as 6°C higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4°C. Below 29.4°C, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9—15.6°C. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7°C.
In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6—41.7°C. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.
1.Why can humans keep stable body temperatures in different seasons?
A. Because their bodies are unusually efficient.
B. Because they experience different climates.
C. Because they can adjust to cultural patterns and technologies.
D. Because they have internal temperature regulating systems.
2.What does Paragraph 2 mainly discuss?
A. The dangerous effects of hypothermia.
B. The change of body temperature.
C. The survival of the Swedish woman.
D. The regulating systems of natural temperature.
3.People are unlikely to survive under the body temperature .
A. higher than 34.4°C B. lower than 29.4°C
C. between 40.6—41.7°C D. between 34.4—37°C
4.What is the best title for the passage?
A. Surviving in an ice trap
B. Getting to know hypothermia
C. Adapting to climate extremes
D. Changing core body temperature
高三英语阅读理解中等难度题查看答案及解析
Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures（核心体温）in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity（湿度）.
In very cold climates, there is a constant danger of developing hypothermia（低体温）, which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0°C. However, differences in persons and even the time of day can cause it to be as much as 6°C higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4°C. Below 29.4°C, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6°C. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7°C.
In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7°C. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.
1.Why can humans keep stable body temperatures in different seasons?
A．Because their bodies are unusually efficient.
B．Because they experience different climates.
C．Because they can adjust to cultural patterns and technologies.
D．Because they have internal temperature regulating systems.
2.What does Paragraph 2 mainly discuss?
A．The dangerous effects of hypothermia.
B．The change of body temperature.
C．The survival of the Swedish woman.
D．The regulating systems of natural temperature.
3.People are unlikely to survive under the body temperature .
A．higher than 34.4°C B．lower than 29.4°C
C．between 40.6-41.7°C D．between 34.4-37°C
4.What is the best title for the passage?
A．Surviving in an ice trap
B．Getting to know hypothermia
C．Adapting to climate extremes
D．Changing core body temperature
高三英语阅读理解中等难度题查看答案及解析
Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity (湿度).
In very cold climates, there is a constant danger of developing hypothermia, which is a life-threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0°C. However, differences in persons and even the time of day can cause it to be as much as 6°C higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4°C. Below 29.4°C, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6°C. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7°C.
In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life-threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7°C. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.
1.What keeps our body temperature stable?
A. Culture and technologies.
B. The stable earth temperature.
C. Our strong determination.
D. Some kind of in-body system.
2.What is a Swedish woman mentioned for in the text?
A. Proving the strength of life.
B. Arguing against some conclusion.
C. Showing the limit on humans’ body temperature.
D. Introducing an exceptional case about our body temperature.
3.Which of the following may cause hyperthermia?
A. Extreme climates.
B. Very cold climates.
C. Controllable infections.
D. Temperatures below 29.4°C.
4.What can be a suitable title for the text?
A. Humans’ Temperature Regulating System
B. Changes of Body Temperatures
C. Humans’ Temperature
D. A Ice Trap Survivor
高三英语阅读理解中等难度题查看答案及解析
Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures（核心体温）in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity（湿度）.
In very cold climates, there is a constant danger of developing hypothermia（低体温）, which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0°C. However, differences in persons and even the time of day can cause it to be as much as 6°C higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4°C. Below 29.4°C, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9—15.6°C. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7°C.
In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6—41.7°C. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.
1.Why can humans keep stable body temperatures in different seasons?
A. Because their bodies are unusually efficient.
B. Because they experience different climates.
C. Because they can adjust to cultural patterns and technologies.
D. Because they have internal temperature regulating systems.
2.What does Paragraph 2 mainly discuss?
A. The dangerous effects of hypothermia.
B. The change of body temperature.
C. The survival of the Swedish woman.
D. The regulating systems of natural temperature.
3.People are unlikely to survive under the body temperature .
A. higher than 34.4°C B. lower than 29.4°C
C. between 40.6—41.7°C D. between 34.4—37°C
4.What is the best title for the passage?
A. Surviving in an ice trap
B. Getting to know hypothermia
C. Adapting to climate extremes
D. Changing core body temperature
高三英语阅读理解中等难度题查看答案及解析
Companion planting is the idea that some kinds of plants can help each other grow. Plants that are compatible together generally have similar needs in terms of nutrients, soil and moisture levels.
Advice about which plants are compatible is sometimes based more on tradition than proof. But experts say there is evidence to support certain combinations. These can improve harvests, reduce disease and help with pest control by attracting helpful insects.
For example, some kinds of soil bacteria take nitrogen from the air and make it into a form that plants can use. The plants hold the nitrogen in their roots. Legumes（豆科植物）are especially good at this nitrogen（氮）-fixing. Then any crops that share the same space with the legumes can get the nitrogen when the roots are broken down.
Beans and potatoes can also share territory well because their roots reach different levels in the soil. Deep-rooted vegetables get nutrients and moisture from lower down in the soil, so they do not complete with plants with shallower roots.
But some plants placed together may harm each other’s development. For example, tomatoes do not like wet soil but watercress does, so you would probably want to keep them separated.
Some kinds of produce should be kept apart even after being harvested. This is because of ethylene gas（乙烯气体）. Ethylene is a plant hormone（激素）that can cause some foods to ripen too quickly. Apples release ethylene gas. Apricots, melons and tomatoes also release a lot of ethylene. Some vegetable are easily affected by ethylene, including asparagus, broccoli, cabbage and cucumbers.
This risk of ripening too soon is why markets often separate high ethylene-producing foods from those that are sensitive to the gas. But if you put an apple in a bag with a green banana, the ethylene from the apple will make the banana ready to eat sooner.
What about peaches, plums and nectarines? These kinds of fruit do not need any help from an apple—they release enough ethylene to ripen themselves. But that does not mean there is no way to get the job done faster.
Growers suggest placing the fruit in a fruit bowl or in a paper bag with the top folded over. Keep the fruit at room temperature, out of direct sunlight. Once the fruit is soft enough, either use it or put it in the refrigerator to keep it from getting too ripe.
1.Companion planting refers to the idea that ________
A. some crops can grow together to benefit each other.
B. some crops have the similar needs of nutrients, soil and water level.
C. some plants can damage each other if grown together.
D. a good farming method to prevent natural disasters.
2.According to the text, ________cannot grow together.
A. beans and potatoes B. tomatoes and watercress
C. legumes and corns D. rice and sugarcane
3.What is the function of ethylene?
A. To improve the quality of fruits. B. To produce a poisonous gas.
C. To keep vegetables fresh. D. To make fruits ripe earlier.
4.The text is most likely to be taken from ________.
A. a newspaper of medicine B. a magazine of biology
C. a journal of agriculture D. a travel report
高三英语阅读理解中等难度题查看答案及解析