下列原因不能造成埋钻事故的是（）。
A、孔壁跨塌
B、岩粉沉淀
C、泥浆泵排量不足
D、以上均不能
参考答案：D
— I'm sorry, I've left my credit card home, so I don't have enough money for the meal.
— Take it easy．_____[ ]
A. It's a piece of cake.
B. It's my pleasure to pay you.
C. It's my treat.
D. It's at your expense.
对于拆卸后还要重复使用的滚动轴承，拆卸时不能损坏轴承的（）。
A、内圈
B、外圈
C、滚动体
D、配合表面
