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

在线课程B
试题分析：考查非限制性定语从句。根据逗号可知，是非限制性定语从句，what不用于定语从句，排除C；that不能用于介词后，排除D；most of them不能引导从句，排除A。如果逗号后有and，说明是两个并列分句，则选择A。故选B。