如果钻杆是内加厚的,那么它对钻井液的流通有什么影响?
参考答案:
如果钻杆是内加厚的,那么它通过的钻井液的阻力就大,泵压就高,消耗的泵公里就多。
南宋时期,有一位阿拉伯商人运载一批香料到广州销售。他到广州后应到哪一机构办理手续( )
A.蕃学
B.蕃坊
C.蕃市
D.市舶司
—Ann isn’t going out this evening,is she?
—________.She has to stay at home to finish her task.
A.Yes,she does
B.No,she doesn’t
C.Yes,she is
D.No,she isn’t