问题详情：
用所给词的适当形式填空
1. The boy is too young to know the _________(dangerous) of smoking.
2. How _________ （excite）we feel!
3. Don’t worry. I remember ________ (shut) the window just now.
4. He ________ (come) back in an hour.
5. ________ (travel) by bus takes longer.
【回答】
er ted ting elling
知识点：构词法
题型：完成句子
