| 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 |