题干

下表中反映的现象出现的原因是(    )

年份

美国对华出口(百万美元)

中国对美出口(百万美元)

1972

60

32

1975

304

156

1980

3755

1059

1985

3855

3840

A:中美建交

B:周恩来对“文革”的抵制

C:中国对经济体制的调整

D:中美关系正常化

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答案(点此获取答案解析)

D

同类题4

阅读理解

C

    Bigger isn't always better. Many scientists will agree. This year the Nobel Prize gave the biggest prizes to findings on the smallest things. Self-eating cells

    This year's winner of the Nobel Prize in Medicine is from Japan. According to his research, cells (细胞) sometimes "eat" themselves to keep healthy. In other words, cells can break down old ones and use the useful parts to make new cells, or to fight off viruses (病毒). This new finding could help scientists fight many diseases.

Small machines

    Three scientists from France, the United Kingdom and the Netherlands (荷兰) won the Nobel Prize in Chemistry for their work on small machines. How small? Well, they are a thousand times thinner than a strand (缕) of hair. We can't see them with only our eyes! This technology will open a whole new world for us. For example, we could make very small robots in the future. A doctor could put them into our body. Like policemen, the robots look for the ill parts in our body, and send the medicine right there.

Super-state

As teachers said in your physics class, most things in the world are in three states: solids (固体), liquids (液体) and gases . But at very low or high temperatures, things can turn into a strange state. For example, break down things to their smallest pieces and we get "atoms" (原子). Like Lego building blocks, atoms usually add up to become a 3-D thing, like a box. But atoms in the strange state don't. They stay together and become a flat thing, like a piece of paper.

    This is a new finding of three British-born scientists. And they won the Nobel Prize in Physics this year. They hope to use things in this strange state to make new materials.

About the Prize

    The Nobel Prize was started by Swedish inventor, Alfred Nobel in 1895. It gives prizes to great science research and the people behind it. Every year in October, the Royal Swedish Academy of Sciences decides who wins. It includes six prizes: chemistry, physics, physiology (生理学) or medicine, peace, literature (文学) and economic. This year each winner gets a medal and prize money of more than 6 million yuan.

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