钨极内缩量对等离子弧的压缩程度有影响，内缩量过小时，等离子弧的压缩程度将（）
A.加强
B.为零
C.减弱
D.不变
参考答案：C
读句子，选答语。
( )1. What's the weather like today?
( ) 2. Is this your dog?
( )3. How many cows do you have?
( )4. How much is the coat?
( )5. Are they horses?
A. I have two.
B. Yes, they are.
C. No, it isn't.
D. It's sunny today.
E. It's ninety yuan.
服务员在准备会谈场地时，使用（）型的台面应铺台布。
A."0"
B."口"
C."I"
D."T"
