当流体温度升高时，流体的密度将（）。
A、不变
B、增大
C、变小
参考答案：C
— Would you mind me _____?
— _____. Do it as you like please. [ ]
A. to play the piano, Good idea
B. playing the piano, Of course not
C. playing the piano, Of course
D. play the piano, All right
下列免疫分子具有特异性作用的是（）
A.Ab
B.IL-1
C.IL-2
D.IFN
E.TNF
