Question

      will do good to a senior student to do a part-time job when she wants to know more about society

A．As

B．It

C．That

D．He

Answer 1

B

试题分析：考查it做形式主语，句意：当高中生想了解社会的时候，做兼职工作对他是有好处的，it指代to do a part-time job，选B。
点评：为了避免句子主语太长，显得头重脚轻，英语中往往用it做形式主语，代替不定式，动名词或从句，这也是英语的一大特点。