is mentioned above,the number of the students in senior

问题描述:

is mentioned above,the number of the students in senior
is mentioned above,the number of the students in senior high schools is increasing
a that b as c which d it

选择B 非限制性定语从句,指代下文全部内容,“如上所述,高中生的人数在增长”
如果选D it的话需要写成 It is mentioned that the number of the .