by [from] the sound of it [things]
（見聞きした）状況からすると
by the thousand
千（個）単位で
by the time babies are [reach] 6 months (of age)
赤ん坊が６か月になる頃までに（は）
by the trial-and-error method
試行錯誤方式で
By the way, have you received that letter yet?
ところであの手紙はもう受け取りましたか
by the week
週決めで
by the year
年決めで
by then
その時までに
By then it was close to midnight.
その時には真夜中近かった
by these presents
本証書により
