如图所示为铜锌原电池，下列有关说法不正确的是（） A．锌_爱下问搜题

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问题选择题

如图所示为铜锌原电池，下列有关说法不正确的是（　　）

A．锌片作负极

B．铜片上有气泡

C．电子由铜片经导线流向锌片

D．一段时间后，溶液中氢离子的物质的量减小

答案

A．该装置中锌易失电子作负极，故A正确；

B．铜作正极，正极上氢离子得电子生成氢气，所以Cu上有气泡生成，故B正确；

C．电子从负极沿导线流向正极，即电子从负极锌沿导线流向正极铜，故C错误；

D．正极上氢离子得电子发生还原反应生成氢气，所以一段时间后，溶液中氢离子的物质的量减小，故D正确；

故选C．

阅读理解

Naim, from Turkey(土耳其), is a great Olympic weightlifting hero. He was the first weightlifter to win a gold medal in three Olympic Games. In 1996, when he won his third gold medal, he lifted a total of 335 kilograms and set a world record.

Patty is the world’s top aerobatic(特技) flyer in the USA. She entered her first flying competition in 1984. She became the first woman to win the title of US National Aerobatic Champion in 1991. And she did the same again in 1992 and 1993.

Ahmed is an Egypt’s champion. He is one of the best tennis players in the world today. In 1992 he entered the world rankings(排名). Four years later, he became an international sports superstar. Millions of people were amazed by his speed and skill.

Lai-Shan, Hong Kong’s greatest sports hero, started windsurfing at the age of 15. She competed in the Olympics in Barcelona in 1992, but came in eleventh place. When she competed a second time in the Olympics, in 1996, she won a gold medal.

小题1:Ahmed was famous for __________.

A．windsurfing

B．weightlifting

D．playing tennis

小题2:Patty was a champion in_________.

小题3:Both Lai-Shan and Naim succeed at the Olympics _________.

单项选择题

以下检查中，哪项是心脏瓣膜病的首选检查方法（）

A.MRI

B.D-US

C.CT

D.X-ray

E.冠脉造影