问题 单项选择题

防止血标本溶血下列哪项错误

A.选用干燥注射器和针头

B.避免过度震荡

C.采血后去针头沿管壁将血液和泡沫缓慢注入

D.标本应及时送检

E.需全血标本时,应采用抗凝管

答案

参考答案:C

解析:不应将泡沫注入。混有泡沫的血标本,放置一定时间后泡沫破裂或迅速干燥,造成血细胞破坏而发生溶血。

阅读理解

阅读理解。

     "Millions of young people will lose their hearing in five years if they listen to MP3 or MP4 players at

a too high voice every day," scientists say recently.

Do you often listen to MP3 players at a too high voice? Are you frightened to hear this?

     The sizes of MP3 players are very small, but small MP3 players make it easy to take hundreds of

songs with you. So many young people carry them and listen to music every day. MP3 players are very

popular among students.  

     The scientists say teenagers should be far from high volume (音量), including mobile phones' noise.

A study says, "High volume and long listening time can cause hearing problems." They think if young

people listen at more than 89 decibels (分贝) every day, they will lose their hearing in five years. A

scientist said, "So many young people often use personal music players and mobile phones at a high

voice. I am afraid that they may be losing their hearing.

     So let's turn our MP3 players down!

1. According to the passage, which of the following is true?

A. Scientists tell young people to turn off their MP3 players.

B. Teenagers will lose their hearing if they listen to hundreds of songs in MP3 players.

C. A person will lose hearing in 5 years if he or she listens to an MP3 player every day.

D. The mobile phone can also cause hearing problems if we don't use it correctly.

2. The underlined word "they" (Paragraph 4) most probably refers to ______.

A. scientists  

B. MP3 players

C. mobile phones

D. teenagers

3. Which might be the best title for this passage?

A. Turn your MP3 players down!

B. Never use MP3!

C. How to protect your hearing.

D. Young people's hearing.

多项选择题