为什么是 by hand 不是 by hands

为什么是 by hand 不是 by hands be picked by hand 被用手采摘 为什么是hand不是hands? hand by hand 英语翻译为什么是by next week.不是in next week. Father By The Hand in that way 和by这里为什么是in不是by? “at hand,in hand,on hand,by hand”分别是什么意思? by hand为什么不说by hands 请问下hand by hand的意思 是with hand 还是by hand? hand by hand,never get lost! by hand 与 by the hand的区别 by hand 与 by the hand的区别 ●hand by hand 手拉手,heart by heart take sb by the hand Father By Thy Hand 歌词 shake sb by the hand make the cards by hand