请示停炉压火前的锅炉水位应保证在正常水位()以上。
A.30~50mm
B.20~30mm
C.10~20mm
D.50~60mm
参考答案:A
I don't think it's good to copy other's homework.You should ________ it.[ ]
A.get over
B.get on
C.get up
D.get off
Mr Robert is _____ our teacher. He is our friend. [ ]
A. other than
B. rather than
C. more than
D. less than