下面不是塑件中圆角的作用是（）。
A、避免应力集中，提高塑件强度
B、有利于充模
C、有利于改善熔接痕的位置
参考答案：C
-Do you think English is _________ math?
-I think so.[ ]
A. as more important as
B. as the most important as
C. as importance as
D. as important as
高处作业均须先（）或（）措施方可进行。
