Question

    Hacking isn’t just for computers and smart phones. According to a study, scientists have found a way to hack a plant’s genes in order to make it use sunlight more quickly. Someday, the results could increase the number of food produced around the world.

Scientists used tobacco plants in the study because it is easy to change the plants^’ genes. Hacked plants are larger than normal plants.

Photosynthesis is the word used to describe how plants use sunlight, water and carbon dioxide to make their own food. Scientists say this is a very slow process. Plants use less than 1 percent of the energy. But by hacking a plant’s genes, the scientists were able to increase the amount of leaf growth on plants between 14 and 20 percent. Scientists hacked the plant’s protective system. Normally, this system starts when a plant gets too much sunlight When the plant senses the light, it creates more leaves. When the plant is in shade, the protective system is turned off. But the process is slow.

The new study sped up the process by changing the plant’s genes, the protective system turned on and off more quickly than normal. As a result, leaf growth on the plants scientists used in the study increased. Leaf growth on two plants increased by 20 percent, while leaf growth on a third plant increased by 14 percent. Scientists conducted the study on tobacco plants. But they think the genetic changes would produce the same results in corn and rice.

Agriculture professor Tala Awanda said the study makes sense，but cautioned the yield（产量）might not be quite so high for conventional food crops. Still，she added in an email,^” this study remains a breakthrough,”

1.Which of the following is true according to Paragraph 1 ?

A. We can find hacking only in digital devices.

B. A plant’s genes can be changed by hacking.

C. Hacking has been used in improving food production.

D. Hacking can be used to change whatever you want.

2.Why did scientists choose tobacco plants to study?

A. Because they are very easy to get.

B. Because their genes are easy to change.

C. Because they are larger than other plants.

D. Because they can absorb sunlight quickly.

3.What do we know about photosynthesis?

A. It helps plants to produce energy.

B. It is regarded as a productive system for plants.

C. It can increase leaf growth on plants by 14 percent.

D. It is made up of sunlight，water and carbon dioxide.

4.We can learn from Paragraph 4 that changing the plants' genes proved____.

A. useless B. deadly

C. effective D. unrealistic

5.What is Tala Awanda’s attitude toward the study?

A. Doubtful. B. Neutral.

C. Objective. D. Critical.

Answer

1.B

2.B

3.A

4.C

5.C

【解析】

本文是一篇说明文，介绍了科学家通过研究发现了一种通过破解植物基因使其更快地利用阳光的方法，这种方法对提高粮食产量是个重大突破。

1.细节理解题。根据第一段中的“scientists have found a way to hack a plant’s genes in order to make it use sunlight more quickly.”可知，科学家发现一种破解植物基因的方法，可以使植物更快地利用阳光，由此可知，植物的基因可以通过破解来改变，故B项正确。

2.细节理解题。根据第二段中的“Scientists used tobacco plants in the study because it is easy to change the plants’ genes”可知，科学家在研究中选择使用烟草植物是因为它们的基因很容易改变，故B项正确。

3.细节理解题。根据第三段中的“Photosynthesis is the word used to describe how plants use sunlight, water and carbon dioxide to make their own food.”可知，光合作用这个词用来描述植物如何利用阳光、水和二氧化碳制造自己的食物，由此可知，光合作用能帮助植物产生能量，故A项正确。

4.细节理解题。根据第三段中的“As a result, leaf growth on the plants scientists used in the study increased.”可知，结果，科学家在研究中使用的植物叶片生长量增加了，由此可知，破解植物的方法证明是有效的，故C项正确。

5.推理判断题。根据最后一段中的“the study makes sense，but cautioned the yield（产量）might not be quite so high for conventional food crops. Still，she added in an email,” this study remains a breakthrough,”可知，Awanda说这个研究很有意义，但她警告说对传统农作物来说，产量可能不会那么高，最后她还说不管怎样，这项研究仍是一个突破，由此可知Awanda对这项研究持客观态度，故C项正确。

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