Therearetreeson_____sidesoftheriver.A.eachB.bothC.everyD.neither

There are trees on _____ sides of the river.
A.each B.both C.every D.neither

B
两边是both

both on both sides (复数） of the road/ street/ river... on either/ each side (单数) of the road/ street/ river... 街道，河流等只有两条边， 所以要从both either each 中选择 两个以上用 every(接单数）， all （接复数） 如： on every side of the playground = on all sides of the playground 请及时采纳，不懂继续问 *^__^* 祝学习进步! 谢谢！