精馏塔的10%漏液量是塔正常操作的()气速。
A、上限
B、下限
C、正常
D、中间
参考答案:B
"Is Tom going to our party this evening?" "No, I ___." [ ]
A.don't think so
B.think not
C.think no
D.don't think yes
轴流泵中有()和推力轴承两种。