手术区皮肤的消毒范围，应包括切口周围（） A.10cm B.15cm C.20cm

I have _____ work to do that I can't go out with you. [ ]

A. much too

B. too much

C. so many

D. so much

预计个人职业照射剂量大于多少mSv／a（年）才需要进行个人剂量监测（）。

A.1

B.5

C.10

D.50

E.100

对于克劳斯反应，下列叙述中正确的是（）。

A、使用催化剂不能改变反应速度

B、使用催化剂能提高反应速度

C、改变压强对反应速度没有影响

D、提高酸气硫化氢浓度不能提高反应速度

11型微机保护中3U0的取用原则是（）。

Oh, You're back at work? How was your holiday? （）

A.We had rain every day and stayed at the hotel most of the time.

B.The ten-day holiday was not long enough.

C.I was missing you when I was on holiday.

D.I heard you were on holiday, too.