Mr Smitk is busy working at school all day(改成同义句)

问题描述:

Mr Smitk is busy working at school all day(改成同义句)

Mr. Smith spends all day working at school.

Mr Simitk had been working at school all day.

最简单而常用的变化是:
Mr Smith is busy working at school all day.
= Mr Smith is busy with the work at school all day.

Mr Smith kept himself working all day at school