According to entomologists, single locusts are quiet creatures, but when locusts are placed with others of their species, they become excited, change color, vibrate, and even hum.
(A) when locusts are placed with others of their species,
(B) when placing them with others of their species, then
(C) locusts, when placed with others of their species,
(D) placing them with others of their species,
(E) placed with others of their species, then
技能get: 状语从句的省略，代词， the Intended Meaning
莎莉小姐姐
正确答案 A