题目内容
—I didn’t see you at Olympic Sports Center this morning. What happened?
—Sorry, I the exchange students around our school then.
A. showed B. was showing C. am showing D. will show
B 【解析】句意：——今天早上我在奥运会体育中心没有看见你。发生了什么？——对不起，我那时正领着交换生参观我们学校。根据时间副词then可知此处用过去进行时，故选B。
The population of Earth is still going up. There will be less and less good land for growing crops in the future. People worry that there will not be enough food for everyone in the middle of this century.
Recently scientists have discovered one strange plant
named fedtschenkoi（玉吊钟）may help. It can absorb（吸收）carbon dioxide(CO₂)
at night. It only needs 10 times less water than food plants like beans. This means it
can grow in the desert(沙漠).
In which ways could this plant help us?
Since deserts are increasing in size because of the changes in Earth’s climate, growing plants there will be more and more important. Although it is dangerous to
eat this plant, scientists can still study something about it: how it absorbs CO₂ at
night while many other plants only do this during the day, and why it is suited to the
desert.
There is another direction to take the research in. Producing a desert plant to eat
will be difficult, but there is still possibility to use the genes(基因)from this plant and put them into food plants.
The other way is to grow this type of plant for fuel(燃料). At the moment we
grow plants for fuel in good land. If we do it in deserts instead, more good land can be used to grow plants for food.
Desert plants have special qualities, which could be an answer to our future food
or energy needs. Scientists are working hard on it.
The Desert Plant Could Help | |
The problems of the future | ◆The population on Earth is becoming 1. than before. ◆There is less and less 2. land for growing crops. ◆There will not be enough food in the future, which makes people 3. |
The discovery of the scientists | ◆It is an 4. plant named fedtschenkoi. ◆Food plants like beans need 10 times 5. water than it does in deserts. |
The ways it could 6. us | ◆The scientists are studying how it absorbs CO₂ and why it is 7. for living in desert. ◆It is 8. to use genes from one plant and then put it inside another. ◆It will be better if we can grow plants for fuel in deserts 9. than in good land. |
Conclusion | ◆Because desert plants have special qualities, it may 10. our food and energy problems in the future. |
