Bill Gates was born on October 28, 1955. He grew up in Seattle, Washington. He was a very clever boy. His favorite subjects at school were science and math. When he was 13, he started to play with computers. At that time, computers were large machines. Once he was very interested in a very old computer. He and some of his friends spent lots of time doing unusual things with it. In the end, they worked out a software program with the old machine. Bill sold it for $4,200 when he was only 17.

In 1973, Bill went to Harvard University(哈佛大学). In his third school year, he left Harvard to work for a company called Microsoft. Bill began his company in 1975 with his friend Paul Allen. They thought the computer would come into every office and every home soon. So they began developing(发展) the software for personalcomputers. They improved(改进) the software to make it easier for people to use computers.

小题1:Bill Gates grew up in _______.

A．Canada

B．Australia

C．America

D．Germany小题2:What subjects did Bill like best at school?

A．Science and math

B．Languages and art

C．Math and languages

D．Music and P.E小题3:Bill’s company worked hard at _______.

A．making large machines

B．playing computer games

C．mending old machines

D．developing software小题4:Bill started to play with computers ______.

A．in 1955

B．in 1968

C．in 1973

D．1975小题5:The word “personal” means _______.

A．个人的

B．公众的

C．大型的

D．昂贵的

下列溶液中，属缓冲体系的是（）。

A.0.100mol·dm-3的NH4Cl溶液

B.0.100mol·dm-3的CH3COONa溶液

C.0.400mol·dm-3的HCl与0.200mol·dm-3的NH3等体积混合后的溶液

D.0.400mol·dm-3的NH3与0.200mol·dm-3的HCl等体积混合后的溶液