钻具上架后如何防止钻具过多而滑落？

阳光上的玻璃缸里有水草，养着各种观赏鱼，这个密封的玻璃缸就是一个（　　）

A．生物圈

B．生态系统

C．非生物

D．各种生物的群体

如果在某线圈中放入铁磁性材料，该线圈的自感系数将会（）。

A.不变

B.显著增大

C.显著减小

D.稍减小

关于容量保护电路，下列说法正确的是（）

A.是一次性预置保护，对额定值内的多次累积性过载有一定的效果

B.对一次性预置保护及额定值内多次累积性过载保护同样有效

C.受管电压、管电流二个参量联合控制

D.受管电流、曝光时间二个参量联合控制

E.是一次性预置保护，受管电压、管电流、曝光时间三参量联合控制

阅读理解。

     Do you know of anyone who uses the truth to deceive (欺骗)? When someone tells you something that

is true, but leaves out important information that should be included, he can give you a false picture.

     For example, some might say, "I just won a hundred dollars on the lottery ( * * ). It was great. I took

that dollar ticket back to the store and turned it in for on e hundred dollars!"

     This guy's a winner, right? Maybe, maybe not. We then discover that he bought $200 worth of tickets,

and only on e was a winner. He's really a big loser!

     He didn't say anything that was false, but he left out important information on purpose. That's called a

half-truth. Half-truths are not technically lies, but they are just as dishonest.

     Some politicians often use this trick. Let's say that during Governor Smith's last term, her state lost one

million jobs and gained three million jobs. Then she seeks another term. One of her opponents (对手) says,

"During Governor Smith's term, the state lost one million jobs!" that's true. However, and honest statement

would have been, "During Governor Smith's term, the state had a net gain of two million jobs."

     Advertisers (广告商) will sometimes use half-truths. It's against the law to make false statements so they

try to mislead you with the truth. An advertisement might say, "Nine out of ten doctors advised their patients

to take Yucky Pills to cure toothache." It fails to mention that they only asked ten doctors and nine of them

work for the Yucky Company.

     This kind of deception happens too of often. It's a sad fact of life: Lies are lies, and sometimes the truth

can lie as well.

1. How much did the lottery winner lose?

A. One hundred dollars.

B. Two hundred dollars.

C. Three hundred dollars.

D. Four hundred dollars.

2. We may infer that the author believes people should _____.

A. buy lottery tickets

B. make use of half-truths

C. not take anything at face value

D. not trust the Yucky Company

3. What do the underline words "net gain" in Paragraph 5 mean?

A. final increase

B. big advantage

C. large share

D. total saving

4. What can we know from the example of the Yucky Pill advertisement?

A. False statements are easy to see through.

B. Half-truths are often used to mislead people.

C. Doctors like to act in advertisements.

D. Advertisements are based on facts.

在10Mbit/s传输率情况下，802.3标准中定义最小长度为（）字节。

A.32

B.100

C.200

D.64