1,Her hope is (to win) a gold medal in the 2008 olympic games。为什么不能用winning?2,The policeman warned the young man never (to drive )after drinking。为什么不能用driving3,You are not expected( to work) such long hours。为什么要用不定式?4,The young trees we planted last week require (looking after) with great care。为什么不能用to be looked after?5,Dont forget (returning )this book to john when you see him.为什么不能用to return?6,When i came home last night,i saw my little (seated)on the bed,with his whole attention (fixed )upon the book about harry porter.为什么不能用sitting,fixing?7,the result of the entrance exams was not made (known)to the public until last thursday.为什么不能用to be known?8,he'd like to get it (settled)today while they are at it.为什么不能用settling?9,i have had my radio repaired?为什么用repaired?