土鳖虫的原动物科名是（） A．钜蚯蚓 B．芫青科 C．壁虎科 D．鳖蠊科 E．眼镜蛇

简述相位防溜控制方式。

     Li Denghai, with his muddy boots and tanned(晒黑的) face, may not look like he is one of China's

famous agricultural pioneers. But the 61-year-old man from Shandong Province has made scientific

breakthroughs(突破), which made great contributions to China’s food security(安全). His main work

has been in achieving the higher output of corn production.

     Li, who holds the world record for the highest output of summer corn, once says, "Corn has a life; it

sings and dances. If you listen clearly, it can speak to you." He started his research in 1969 when he was

20 and just dropped out of a high school. He then read an article which pointed that corn output per mu

in the USA was six times higher than that in China. He was shocked and set out to work on just a small

piece of land round the clock to see if he could increase the output. He often went to the field with a

flashlight late at night, if he had been away during the day. By careful nurturing (照料) he managed to

double the output.

     Li Denghai was awarded the "China Award for Significant Contribution to the Maize (玉米) Industry"

in 2005, and the same year the company named after his own name came into the market on the Shenzhen Stock Exchange. Li, however, is never happier than when he is in the middle of his cornfields. "I can forget my tiredness when talk to my corns," he says.

1.When Li Denghai began the study of corn,      .

A. he just graduated from an ordinary high school

B. he was shocked that the corn output in China was so low

C. he was only in his thirties

D. he wasn't really fond of his work

2. In 1960s', if the corn output of 10 mu was 2,000kg in China, the same size field in America could

produce       .

A. 4,000kg

B. 8,000kg

C. 12,000kg

D. 20,000kg

3. The underlined phrase "round the clock" means      .

A. day and night  

B. sooner or later

C. face to face  

D. now and then

4. From Mr. Li's words in this passage, we can learn that      .

A. he is not good at communicating with people

B. he is too tired to go to the corn fields

C. he talks to his corn when feeling lonely

D. he loves his career deeply

5. By mentioning the company on the Shenzhen Stock Exchange, the author means that Mr. Li      .

A. has become very rich

B. has changed into a businessman

C. has succeeded in enlarging his career

D. has been too busy to go on his corn study

下列不出现病理性骨折的是（）

A.骨软化症

B.骨性关节炎

C.骨化性肌炎

D.骨折

E.滑膜炎

断路器的文字符号即（）。

A.QL

B.QF

C.F

D.Fu

白色衬衫是最基本的款式之一，对身材要求相对较高，一般只适合年龄偏小身材偏瘦的女生