焊接电弧是气体的()现象。
A.燃烧
B.对流
C.电离
参考答案:C
— What do you think of his brother?
— I can't _____ him.
[ ]
A. stand
B. mind
C. agree
D. standing
SHAFER转动叶片式驱动器转动叶片的转程为()。
A.85%~95%
B.80%~90%
C.85%~90%
D.75%~85%