学习形成两个或更多的刺激与反应联结，即形成一系列的刺激与反应联结的是（） A.连锁学

已知全集U={1，2，3，4，5，6，7，8} P={3，4，5}  Q={1，3，6} 那么集合{2，7，8}是（　　）

A．P∪Q

B．P∩Q

C．∁_uP∪∁_uQ

D．∁_uP∩∁_uQ

“充电”是指：设备与电源接通，（）负荷。

A.一定带

B.不带

C.可以带

D.其他三个选项都不是

蓝光箱内的灯管使用时间不超过（）

A.300小时

B.400小时

C.500小时

D.600小时

E.700小时

阅读理解

                                                        Obama Still Smokes in Secret

     US President Barack Obama has just made life more difficult for cigarette makers. He has just signed

a law that will set tough new rules for the tobacco industry. The new law gives the US Food and Drug

Administration the power to strictly limit the making and marketing of tobacco products.

     At a White House signing ceremony Monday, Obama said that he was among the nearly 90% of

smokers who took up the habit before their 18 th birthday.

     Obama, who has publicly struggled to give up smoking, said he still hadn't completely kicked the habit.

Every now and then he still smokes in secret.

     "As a former smoker I struggle with it all the time. Do I still smoke sometimes? Yes. Am I a daily

smoker, a constant smoker? No." Obama said at a news conference.

     "I don' t do it in front of my lads．I don ?t do it in front of my family．I would say that I am 95%

cured, but there are times when I mess up, " he said．

     "Once you go down this path, it' s something you continually struggle with, which is exactly why the law

is so important．The new law is not about me, it' s about the next generation of kids coming up．What

we don ' t want is kids going down that path," he said．

     Nearly 20% of Americans smoke and tobacco use kills about 440,000 people a year in the United

States due to cancer, heart disease, and other serious diseases．

1．The new law makes life difficult for              .

A．Obama            

B．tobacco industry

C．White House      

D．US Food and Drug Administratio

2．What do we know about Obama?

A．He no longer smokes．

B．He still smokes as usual．      

C．He began to smoke at eighteen．

D．He is trying hard to give up smoking．

3．According to the passage, Obama is most concerned about           ．

A．children      

B．officials        

C．his family      

D．businessmen

压力容器气密性试验所用气体的温度不应低于＿℃。

A.5 

B.10 

C.15 

D.20