那你觉得把下面这句话里的when充当的的角色放到E里可行么?
GWD28-Q21: 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.
个人觉得选项不是when as的区别;主要是事件发生的时间顺序;
A. when canals and eventually railroads reached into the region, there were substantial supplies of coal that was
B. once canals and eventually railroads reaching into the region, there were substantial supplies of coal having been exported发生在 railroads之前
C. with canals and eventually railroads reaching into the region, there had been substantial supplies of coal with表伴随同时发生 与后面时态矛盾
D. canals and eventually railroads reached into the region, with substantial supplies of coal being
E. !as canals and eventually railroads reached into the region, substantial supplies of coal were
AE的话 应该是substantial supplies of coal的限定于非限定修饰问题吧!