5.The growing speed of a plant is influenced by a number of factors are beyond our contr

问题补充：

5.The growing speed of a plant is influenced by a number of factors, are beyond our control.

A. most of them

B. most of which

C. most of what

D. most of that

答案：

A. most of them

(答案→)B. most of which

C. most of what

D. most of that

解析：factors为先行词，且为非限制性定语从句，所以答案应该选most of which。