英语作业用所给词的适当形式填空

英语作业用所给词的适当形式填空
1Though he is young,he is as ——（forget）as an old man.
2He doesn't know the _(different) between these two two words
3It's said that there were several ___(die)in the road accident
4Listening to music is a good way to __(relax)