为什么是what is she doing for vacation.而不是what does she do for v

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 is she doing for vacation?为什么要用for额? what is she doing for vacation?she is visiting her grandmoth what's she doing for vacation同义句 what does she doing? what's she doing for vacation -----she _____(look) after her What does she do in the morning 和 What is she doing now 前句用 （歌手）what is she doing?what does she do?（用英语回答） what is she doing than for?同义句 what is she doing that for?的同义句是什么 为什么不能说what does she doing?