| at the thought of | 一想起 |
| at this/that rate | 照此情形；如此下去 |
| at times (time) | 有时 |
| at will | 随意；任意 |
| at work | 在工作；上班 |
| at/on sb's heels | 紧跟某人 |
| back and forth | 反复地，来回地 |
| back away | 放弃；退出 |
| back down | 放弃；让步 |
| back off | 后退；软化；减轻；卸下 |
| back out | 退出；收回 |
| back to back | 背靠背；连续，紧接 |
| base on | 基于，以……为根据 |
| bask in sth | 沉浸，沐浴（在赞美、关注等中） |
| be able to do sth. | 能够做 |
| be about to do sth. | 即将，正要（做某事） |
| be free from | 不受…影响 |
| be located in | 坐落于…，位于… |
| be make from | 由……做成 |
| be make up of | 由……组成，由……构成 |