滚珠导轨副的额定寿命为()。
A.50km
B.60km
C.70km
参考答案:A
尽端式车行路长度超过( )m应设回车场。
A.22
B.30
C.35
D.40
This film was made ______ Comrade Kong Fansen. Which of the following is NOT correct?[ ]
A. in honour of
B. in memory of
C. in praise of
D. in charge of