丙酮酸还原为乳酸，提供所需氢的是A．FMNH2 B．FADH2 C．FH4 D．NA

将A、B两句进行比较，说说哪句的表达效果更好，好在哪里。  

A．从前线回来的人说到白求恩，没有一个不佩服，没有一个不为他的精神所感动。  

B．从前线回来的人说到白求恩，个个都佩服，个个都为他的精神所感动。   

_______________________________________

用煮沸法进行消毒，为了提高沸点可加入（）

A.2%的氯化镁

B.2%的氯化钾

C.2%的硫酸镁

D.2%的碳酸钠

E.2%的碳酸氢钠

阅读理解。

     Teens don't understand the big fuss (小题大做). As the first generation to grow up in a wired world, they

hardly know a time when computers weren't around, and they eagerly catch the chance to spend hours online,

chatting with friends, So what?

     But researchers nationwide are increasingly worried that teens are becoming isolated (孤寂), less skillful at

person-to-person relationships, and perhaps numb (麻木) to the cheatings that are so much a part of the e-mail

world. "And a teen's sense of self and values may be changed in a world where personal connections can be

limitless,"said Sherry Turkle.

     Another researcher, Robert Kraut, said he's worried about the "opportunity costs" (机会成本) of so much

online time for youths. He found that teens who used computers, even just a few hours a week, showed

increased signs of loneliness and social isolation. "Chatting online may be better than watching television, but

it's worse than hanging out (闲逛) with real friends," he said.

     Today's teens, however, don't see anything strange in the fact that the computer takes up a central place in

their social lives, "School is busy and full of pressure. There's almost no time to just hang out." said Parker Rice,

17. "Talking online is just catch-up time."

     Teens say they feel good about what they say online or taking the time to think about a reply. Some teens

admit that asking someone for a date, or breaking up, can be easier in message form, though they don't want

to do so. But they insist there's no harm.

1. The researchers argue that _____.

A. teens may develop a different sense of values

B. nothing is wrong with teens'chatting online

C. teens can manage their social connections

D. spending hours online does much good to teens

2. The text mainly deals with _____.

A. use computers properly

B. improve their school work

C. develop an interest in social skills

D. reduce their mental pressures

3. The text mainly deals with _____. 

A. teens' pleasant online experience

B. teens' computer skills and school work

C. the effects of the computer world on teens

D. different opinions on teens' chatting online

4. The purpose of the text is to _____.

A. describe computer research results

B. draw attention to teens' computer habits

C. suggest ways to deal with problem teens

D. discuss problems teens have at school

患者，女，34岁。因1个月来发热、乏力、咳嗽，1天来左眼突然失明来院。既往有心脏杂音。查体：体温37.9℃，脉率96次/分，血压128/75 mmHg，左眼视力消失，双肺(-)，心界不大，心尖部3/6级收缩期吹风样杂音，肝未及，脾肋下可及。化验：Hb 96g/L，WBC 12.8×10⁹/L，尿蛋白(±)，镜检RBC 1～3/HP。

该患者不可能出现的体征是

A．Roth斑 B．杵状指
C．水冲脉
D．Osier斑

指标