Yuan Longping was a great Chinese scientist. When he was a little boy, many people in China didn’t have enough rice to eat. He had a big dream: “I want to grow rice plants as tall as trees, so that everyone can have enough food!” To make his dream come true, Yuan studied and worked very hard. Finally, he made a new kind of rice — hybrid (杂交的) rice! Because of him, hundreds of millions of people are no longer hungry. 

1.1.Yuan Longping was a ______.

A teacher

B scientist

C doctor

D cook

解析：选B。B细节理解题。文章第一句“Yuan Longping was a great Chinese scientist.”就点明袁隆平的身份，他是一名科学家。故选B。

2.2.In Yuan’s dream, rice plants grew as tall as ______.

A hills

B houses

C trees

D walls

解析：选C。C 细节理解题。根据文中的“He had a big dream: ‘I want to grow rice plants as tall as trees, so that everyone can have enough food!’”可知，袁隆平的梦想是种出的水稻像树一样高大。故选C。

3.3.Yuan Longping made a new kind of ______.

A fruit

B rice

C bread

D meat

解析：选B。B细节理解题。根据文章中的“Finally, he made a new kind of rice”可知，袁隆平研发出了一种新型的水稻。故选B。

4.4.What is the main idea of the passage?

A A special plant.

B A big country.

C A great person.

D A nice dream.

解析：选C。C主旨大意题。整篇文章都在介绍袁隆平这位科学家，他是一个伟大的人。故选C。