选B.
every minute,____ full use of _____ our lessons,will do good to us students.
先划分句子成分吧,整句话的主语是 every minute,谓语是will do good to us students.
主谓之间的从句实际上是一个省略形式,完整结构是“ when every minute is made full use of to study our lessons”
从句的主语是every minute,谓语是is made full use of ,谓语中有系动词be,to study our lessons是目的状语.
这里出现了一个语法项目,“当从句主语和主句主语一致,而且从句谓语中有系动词be的时候,可以省略从句的主语和系动词”.
省略之后的从句就是 “when made full use of to study our lessons”
整句话的意思是“众所周知,当每一分钟都被充分利用于学习时,每一分钟都对我们大有裨益”
所以答案出来了 B