减速箱和变速箱的润滑油应定期更换,对连续运行的减速箱应经常检查油温,不能超过()。
A.90℃;
B.60℃;
C.80℃;
D.100℃。
参考答案:B
_______ in the city for thirty years, the old man moved back to the countryside.
A.Having worked
B.Working
C.To have worked
D.To work
买方提出的发盘习惯上称为______
A.发价 B.要约C.递盘 D.还盘