使金属钠产生光电效应的光的最长波长是0.50m，因此金属的逸出功W=J，现在用频

阅读理解

      A long time ago people thought that the Sun went round the Earth. In

some countries people even said that the Sun was a god(神). They thought the god drove across the sky each day on a golden horse. Now we know the Earth goes round the Sun. It takes the Earth a year to go all way round the Sun.

Today man even know how far it is for the Earth to go round the Sun. They

tell us that the Earth travels over a thousand miles a minute on its journey

round the Sun. 

     The Sun is really a star. It is much bigger than the Earth and it is very hot. Some people have been to the moon but we know that no one can ever go to

the Sun. It is far too hot for people to live anywhere near it. The Sun is three hundred thousand times(倍)heavier than the Earth and more than 1 million

times larger.

1. A long time ago, people said the Sun was _____.

A. a golden horse of god    

B. a god on a golden horse

C. a god with golden dress    

D. a god and a golden horse

2. People can never live anywhere near the sun because it is _____.

A. too hot      

B. too far      

C. too small      

D. too heavier

3. The Earth travels over _____ miles an hour.

A. 1, 000    

B. 100, 000      

C. 6, 000, 000      

D. 60, 000

4. One year is _____.

A. the time for the Earth to turn round.    

B. the time the Earth travels one thousand miles.

C. the time the Earth goes round the Sun one circle(圈,周).  

D. the journey of the Earth.

5. Which of the following is TRUE? _____

A. The moon is the planet of the Sun.    

B. One day man can land on the Sun.

C. The Sun is a star like other stars.    

D. The moon is the nearest star to us in space.

采集血清标本时不正确的是

A．选用干燥试管

B．采血后立即将血液射入试管内

C．勿注入泡沫

D．避免震荡

E．防止溶血

An analyst does research about cost of capital. All else constant, if a company's marginal tax rate increases, the weighted average cost of capital most likely:（）

A. decreases.

B. remains unchanged.

C. increases.

上海养老保险是不是也是缴纳15年就可以领取了呢？

人体内环境稳态的维持，依赖于神经—体液—免疫调节机制，信息分子是它们之间发生联系的“语言”。下图是人体某些信息传递机制的模式图，字母A~C表示信息分子，数字表示相关生理变化。请据图回答：

模式图中发生的生理变化①是肾小管、集合管对（）增强，②是B淋巴细胞增殖分化产生（）。