每钻进()米及见可采煤层底板后,需丈量钻具全长,以校正钻孔深度。
A、30
B、50
C、100
D、150
参考答案:C
改错
Where doesyour cousin live on? ( )
A B C
We would have called a taxi yesterday if Harold ______us a ride home.
A.didn't offer
B.wouldn't offer
C.hasn't offered
D.hadn't offered