by accident 偶然
at one time 曾經,一度;同時
at present 目前,現在
at sb's disposal 任...處理
at the cost of 以...為代價
at the mercy of 任憑...擺布
at the moment 此刻,目前
at this rate 照此速度
at times 有時,間或
back and forth 來回地,反復地
back of 在...后面
before long 不久以后
beside point 離題的,不相干的
beyond question 毫無疑問
by air 通過航空途徑
by all means 盡一切辦法,務必
by and by 不久,遲早
by chance 偶然,碰巧
by far 最,...得多
by hand 用手,用體力
by iteslf 自動地,獨自地
by means of 用,依靠
by mistake 錯誤地,無意地
by no means 決不,并沒有
by oneself 單獨地,獨自地
by reson of 由于
by the way 順便說說
by virtue of 借助,由于
by way of 經由,通過...方法