决定做什么,怎么做,什么时间做,去哪里,怎么去等问题都会用到“decide+wh-词＋to do"这个结构,例如：
I haven't decided what to buy.
She has decided when to leave for Shanghai.
We haven't decided when or where to have the meeting.
Have you decided where to spend your winter holidays?
I haven't decided how to go to school tomorrow.