Yuan Longping, "the father of hybrid rice(杂交水稻)", is one of the most important agricultural scientists.He had spent his whole life on hybrid rice.
　　Food was a big problem in China in the past. It was because China had 22% of the world's population, but only 7% of its farmland.In the 1960s, China had serious hunger.Millions of people died because they had no food.Professor Yuan was very sad to see this."How can I help people have enough food?" he thought.He decided to work on a new kind of hybrid rice that had a high output.He and his team studied the rice seeds (种子) day and night.At last, in 1973, they grew a new kind of hybrid rice.This rice is strong.Farmers can grow it in many different kinds of farmland and also in bad weather.It can also fight diseases.Its output is much higher than common kinds of rice.
　　Professor Yuan has already left us, but he will be remembered forever.
（1） What had Yuan Longping spent his whole life on?
A. Population.
B. Weather.
C. Hybrid rice.
D.Apples.
（2） What does the underlined word "output' mean in the second passage?
A.能力
B.质量
C.能源
D.产量
（3） What made millions of people die in the 1960s?
A. No food.
B. Serious diseases.
C. No seeds.
D. No water.
（4） When did they grow a new kind of hybrid rice?
A. In 1960.
B.In 1973.
C. In 1983.
D.In 2020.
（5） Which of the following is TRUE about hybrid rice?
A. Its output is much higher.
B. It is not strong enough.
C. It can't grow in bad weather.
D. It can't fight diseases.