下列属常用的热熨剂的有()。
A.坎离砂
B.熨药
C.粗盐
D.黄砂
E.以上都是
参考答案:E
I'm afraid Mr. Harding _____ see you now. He's busy. [ ]
A. can't
B. mustn't
C. shouldn't
D. needn't
用变压器型号KSI的含义为()。