状语从句的省略：主句主语和从句主语一致且从句谓语动词含有动词BE省略从句的主语和BE。When( I was) in Japan, I took many beautiful pictures.I won't go unless (I am) invited.
这么高端！省略句哪怕在研究生阶段除了英语专业也是不用掌握的吧……
