What is she doing for vacation?为什么要用for额?

What is she doing for vacation?为什么要用for额? 为什么是what is she doing for vacation.而不是what does she do for v what's she doing for vacation?中文 what are you doing for vacation?为什么要用for不用on what is she doing for vacation?she is visiting her grandmoth what's she doing for vacation同义句 what are you doing for vacation为什么用ing形式和for啊 what are you doing for vacation .为什么用介词for 而不用on? what are you doing for vacation?doing为什么用ing形式啊 --What is he doing for vacation?---He____(relax) at home. what are you doing for vacation?是什么时态 为什么 What's he doing for vacation?