It is high time that everyone()very hard for the coming national college en-trance examination
问题描述：
It is high time that everyone()very hard for the coming national college en-trance examination
would study
studied
study
studies
答
studied
原因：it is high time that +从句
从句中的谓语动词要么用过去式,要么用should+动词原形,should不可省略