钻孔灌注桩钻孔时使用泥浆起( )作用。
A．悬浮钻渣
B．润滑
C．减少水头损失
D．护壁
参考答案：A,D
根据句意及图片提示完成单词
1. They have______ ( )on Monday.
2. ______ ( )is very interesting.
3. —Can you tell me the time?
—It's twelve ______ ( ).
4. ______ ( )is my favourite subject (科目).
5. We have an a ______ ( ) lesson in the afternoon.
机器语言程序是计算机能直接执行的程序。 ( )
)on Monday. 
)is very interesting. 
). 
)is my favourite subject (科目). 
) lesson in the afternoon.