( )管壁较厚,适用于潮湿、有机械外力、有轻微腐蚀气体场所的明暗配。
A.焊接钢管 B.电线管 C.硬塑料管 D.半硬塑料管
参考答案:A
They _____ 3000 English words by the end of next month. [ ]
A. learned
B. had learned
C. will learn
D. have learned
《廉政准则》对党员领导干部廉洁从政提出了哪些要求?