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)
答
Mr. Smith spends all day working at school.
答
Mr Simitk had been working at school all day.
答
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.
答
Mr Smith kept himself working all day at school