>
back up 支持;倒退
be bent on (upon) 一心想做(某事)
be better of 处境更好;情况转好
be bound to 肯定，注定;一定要; 决心
be composed of 由…组成
be concerned with 关于…，与…有关;参与…
be determined to 坚定;坚决;决心
be fed up with/about 对…厌烦了;讨厌
be fit for 适合
be inclined to 倾向于…;想要
be obliged to (do) 被迫，不得不
be obliged to 感谢
be related to 与…相关的，同…有亲戚关系
be/get tired/sick of 对…失去兴趣;厌烦
be/get used/accustomed to 习惯于
bear/keep in mind 记住;牢记
bear on/upon 对…施加压力;与…有关;对…有影响
before long 很快;不久以后
blow out (使火)熄灭;(轮胎)爆裂
blow up 炸毁;充气;放大(照片);勃然大怒
boil/narrow down (to) 压缩成;归结为;简化为…
break down (机器)发生故障;(计划，谈判等)失败;分析;分解;破除;战胜;(感情)失控，(身体)垮了
break in 闯入;打断;训练;使驯服;使习惯于;
break into 闯入;打断;突然开始…;突然…起来
break out 突然暴发;逃脱