减速箱和变速箱的润滑油，需要定期更换，对连续运动的减速箱应保持油温不超过（
A.100℃；
B.60℃；
C.90℃；
D.80℃。
参考答案：B
____________ late, but also he forgot his books. [ ]
A. Not only did he turn up
B. Not only he turned up
C. Not only did he turn out
D. Not only he turned out
以下是基态原子的电子排布式的是 （ ）
A．1s12s1
B．1s12s12p1
C．1s22s22p6 3p1
D．1s22s22p63 s2
