不能提示心搏骤停的临床表现是（）。 A.颈动脉搏动消失 B.意识丧失 C.呼吸停止

每个液NH₃贮罐有两个（）。

A、安全阀

B、放空阀

C、压力表

D、排污线

第三部分：阅读理解（共20小题；每小题2分，满分40分）

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。

Miss Gorgers taught physics in a New York school. Last month she explained to one of her classes about sound, and she decided to test them to see how successful she had been in her explanation. She said to them, “Now I have a brother in Los Angeles. If I was calling him on the phone and at the same time you were 75 feet away, listening to me from the street, which of you would hear what I said earlier, my brother or you and for what reason?”

Tom at once answered, “Your brother. Because electricity travels faster than sound waves.” “That’s very good,” Miss Gorgers answered; but then one of the girls raised her hand, and Miss Gorgers said, “Yes? Kate.”

“I disagree. Your brother would hear you earlier because when it’s 11 o’clock here and it’s only 8 o’clock in Los Angeles.” Kate said.

1. Miss Gorgers was teaching her class ______.

A. how to telephone      B. about electricity

C. about time zone        D. about sound　

2. Miss Gorgers raised this question because she wanted to know whether ______.

A. it was easy to phone to Los Angeles

B. her student could hear her from 75 feet away

C. her students had understood her lesson

D. sound waves were slower than electricity

3. Kate thought Tom was wrong because ______.

A. clocks in Los Angeles showed a different time from those in New York

B. electricity was slower than sound waves

C. Tom was not good at physics at all

D. Tom’s answer had nothing to do with sound waves

4. Whose answer do you think is correct according to the law of physics?

A. Tom’s. 　　            B. Kate’s.          C. Both A and B. 　　      D. Neither A nor B.

下列哪项不是荆芥的鉴别特征

A．茎方柱形

B．叶互生

C．断面类白色

D．穗状轮伞花序

E．小坚果

Windows N TServer 4.0升级到Windows 2000Server后，Windows NT的备用网域控制器会变成（）。

A.网域控制器

B.用户服务器

C.独立服务器

D.A或B

轨道电路的作用是（）。