改为复合句和简单句
将此句改为复合句：
Lucy hasn't decide which trousers to buy.
Lucy hasn't decide ______ ______ ______ ______buy.
将此句改为简单句：
I don't know how i can gei to the hospital.
I don't know_____ _____ _____to the hospital.
做这种题的技巧是什么啊?