以下不属于D型施工便梁型号的是()。
A.D32
B.D24
C.D20
D.D12
参考答案:A
I didn't have _____ to say, so I said _____.
[ ]
A. something; anything
B. anything; nothing
C. anything; something
D. nothing; something
碳化塔下部堵塞较常发生在(),结疤以()为主。
A、水箱段靠近塔底,NaHCO3
B、笠帽盖底部,NaHCO3
C、水箱段靠近塔底,NH4HCO3
D、笠帽盖底部,NH4HCO3