1. learn ... by heart 用心学习，记住
2. combine ... with ... 使...与...结合/联合
3. in that circumstances 如果那样的话
4. replace ... with ... 用...代替...
5. keep a record of 记录
6. comment on ... 对 ... 发表评论
7. at least 至少
8. expect of/from... 从...当中期待
9. in return 作为回报
10. the survey on ... 关于... 的调查
