The young dancers looked so charming in their beautiful clothes that we tookpictures of th

问题补充：

The young dancers looked so charming in their beautiful clothes that we tookpictures of them.

A. many of

B. masses of

C. the number of

D. a large amount of

答案：

A. many of

(答案→)B. masses of

C. the number of

D. a large amount of

解析：句意：这些年轻的舞者们穿这些漂亮的衣服看起来是如此的迷人，以至于我们给他们拍了很多的照片。masses of大量的，修饰可数名词的复数形式，故选B