1. happen to do sth. 碰巧做某事
2. hardly 几乎不
3. It occurs/occurred to sb. that 某人突然想起
4. in my opinion 在我看来
5. what's more 此外/而且
6. come across 偶遇
7. the healthy 健康人
8. keep quiet 保持安静
9. two cups of water 两杯水
10.It's difficult to carry out the plan. 实施这个计划是困难的