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
网友回答
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。