干选机,给料机的振动电机应保证良好的润滑,应在运转()小时左右补充或更换润滑脂。
A、600
B、300
C、400
D、500
参考答案:D
It is bad ______ to talk with your mouth full.[ ]
A. health
B. ways
C. manners
D. hobbies
He is much better and can now.
A.get ahead
B.get about
C.get along
D.get away