The young dancers looked so beautiful in their new clothes that we took ________ pictures of them.[      ]

A. many of  

B. masses of

C. the number of  

D. a large amount of

用石墨和黄油浸透的棉织调料适合低压水泵上，输送介质在（）℃以下。

A.30

B.35

C.40

D.45