There are so many tall trees in the forest .A. some of them measures over 50 meters B. som

问题补充：

There are so many tall trees in the forest,.

A. some of them measures over 50 meters

B. some of which measuring over 50 meters

C. some of them measuring over 50 meters

D. some of which measures over 50 meters

答案：

A. some of them measures over 50 meters

B. some of which measuring over 50 meters

(答案→)C. some of them measuring over 50 meters

D. some of which measures over 50 meters

解析：考查独立主格。There are so many tall trees in the forest是句子，前后句子没有连词，不能选A;D项应把measures改为measure；所以选C,独立主格。