It’s said that this kind of plant only gives ...

It’s said that this kind of plant only gives off this strange perfume on ________ conditions which the scientists are trying to figure out now.

A. outstanding        B. certain            C. obvious         D. ordinary

高二英语单项填空简单题查看答案及解析

Only that factory ____________ yesterday __________ this kind of machines.

A．we visited; produces                     B．did visited; does it produce

C．we visited; does it produce                D．did we visit; produce

高二英语单项填空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（兼容的，能共处的） 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 vegetables 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

高二英语阅读理解中等难度题查看答案及解析

That kind of plant can be made ______ paper and paper can be made ______ wood.

A. of; of      B. from; of     C. from; into     D. into; from

高二英语单项填空中等难度题查看答案及解析

A new report said that different types of plants can release some chemical into the air to help other plants. These chemical warnings all have the same purpose — to spread information about one plant's disease or infestation so other plants can defend themselves. But exactly how plants receive and act on many of these signals is still mysterious.

In this week’s Proceedings of the National Academy of Sciences, researchers in Japan offered some explanations. They had identified one chemical message and traced it all the way from release to action.

The scientists looked at tomato plants infested by a common pest, the cutworm. The researchers studied leaves from exposed and unexposed plants. They found one compound showed up more often in the exposed plants. The substance is called Hex Vic. When the scientists fed Hex Vic to cutworms, it knocked down their survival rate by 17%. The scientists identified the source of Hex Vic, and sprayed it lightly over healthy plants. Those plants were then able to start producing the cutworm-killing Hex Vic. Researchers confirmed that uninfected plants have to build their own weapons to fight off bugs and disease. How do they know when to play defense? They are warned first by their friendly plant neighbors.

It is a complex tale, and it may be happening in more plant species than tomatoes. It may also be happening with more chemical signals that are still unknown to us. Further studies are needed to increase agricultural efficiency.

1.Which is the way used by plants to warn their neighbors?

A. Using of winds.

B. Identifying the chemicals.

C. Releasing some chemicals.

D. Being exposed early.

2.It can be inferred from the text that ________.

A. farmers may benefit from the further studies

B. the phenomenon may be happening in less plant species than tomatoes

C. there are not chemical signals

D. plants are warned first by their neighbors

3.What’s the function of Hex Vic?

A. It sprays over healthy plants.

B. It shows up more.

C. It cures the disease.

D. It damages the cutworm’s body.

4.The passage is likely to appear in ________.

A. a newspaper advertisement

B. a physics textbook

C. a science magazine

D. a finance report

高二英语阅读理解中等难度题查看答案及解析

根据首字母或中文提示写出单词，并注意所填单词的适当形式。

1.This kind of plant has a wide_____________(分布)。

2.It was an_________________(不可思议的)moment when Chris won the gold medal.

3._______________(假设)you get a place at university, how are you going to finance your studies?

4.The article made no____________(提及)to previous research on the subject.

5.He was known for his____________(慷慨)to his colleagues.

6.A_____________from a novel,the film was a hit after its release.

7.Laurie finds it difficult to r______________to children, which accounts for their frequent quarrels.

8.Rumours began to c____________that the chairman was going to resign.

9.The man is involved in a dispute over the o_____________of the land.

10.This kind of shark will never i________________hurt human beings unless it is cornered.

高二英语单词拼写中等难度题查看答案及解析

. --- This kind of food is said to contain poisonous chemicals.

--- So why not _____ it?

A. murder      B. arrest      C. boycott     D. abolish

高二英语单项填空简单题查看答案及解析

You look very beautiful in this dress and there is only one of this kind left here. I wonder    if you would like to buy ______.

高二英语单项填空中等难度题查看答案及解析

“Neal, listen,” she said, looking straight at him, “I ask you not to get _____ in this kind of matter. It’s none of your business.”

A. caught　　　　　　 B. connected

C. attached　　　　 D. involved

高二英语单项填空中等难度题查看答案及解析

Only the factory ____ yesterday ____  this kind of machines.

A. did we visit; does it produce          B. did we visit; produces

C. we visited; produces                     D. we visited; does it produce

高二英语单项填空简单题查看答案及解析