PON下行波长为（）nm。A、1310 B、1300 C、1490 D、1550

阅读理解。

     Now lots of teenagers like smoking. It's a big problem. Some of them smoke, just for fun and some think

smoking looks cool. Others smoke because there are many people around them that smoke.

     As we all know, smoking is harmful, especially to students. Some teenagers even steal money so that they

can buy cigarettes. Besides, smoking does harm to brains and it can influence studies. Finally, it is bad for

health because it can cause diseases.

     Therefore (因此), we should protect ourselves from smoking. First, we should learn more about the

danger of smoking. Second, we should keep away from people who smoke.

1. Now some teenagers like smoking because ________.

A. smoking is good for them

B. their parents want them to do so

C. they think it is fun

2. From the passage, we know some teenagers steal money in order to ________.

A. buy cigarettes

B. buy books

C. play games

3. Smoking is harmful to ________.

A. brains

B. legs

C. eyes

4. Which of the following sentences is NOT true?

A. Smoking can cause diseases.

B. Smoking can influence studies.

C. We shouldn't keep away from people who smoke.

5. The writer of the passage wants teenagers ________.

A. to smoke

B. not to smoke

C. not to keep away from smoking

关于螺内酯的叙述错误项是：

A．具有抗醛固酮作用

B．对切除肾上腺的动物有效

C．利尿作用弱、慢、持久

D．是排钠能力较低的利尿药

E．用于醛固酮增多性水肿

“嫦娥一号”卫星绕近地点205 km、远地点50930 km、周期为16 h的超地球同步轨道运行时，从近地点向远地点运行的过程中，它的 [ ]

A．动能增大，势能减小

B．动能减小，势能增大

C．动能不变，势能增大

D．动能增大，势能不变

属于技术分析理论的有（）

A.随机漫步理论

B.切线理论

C.相反理论

D.道氏理论

心源性呼吸困难的主要原因是

A．肺循环淤血
B．体循环淤血
C．气道痉挛狭窄
D．呼吸中枢兴奋
E．极度紧张、恐慌