by the pricking of my thumbs
虫の知らせで
by [through] the recommendation of a friend
友人の推薦で
by [at, on] the roadside
路傍に
by the rules
ルールに従って
by the score
まとまって，大量に
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
