铸件尺寸公差及机械加工余量等级有()级。
A.5
B.10
C.15
D.20
参考答案:B
_____ seemed as if nobody knew anything about the matter.
A.This
B.That
C.It
D.One
足太阳膀胱经的穴位数为()
A.45个
B.67个
C.44个
D.69个
E.43个