they took the sick boy to the hospital at once改为被动语态 at once放在哪里,by them 放在哪
问题描述：
they took the sick boy to the hospital at once改为被动语态 at once放在哪里,by them 放在哪
答
The sick boy was taken to the hospital at once by them.
The sick boy was taken by them to the hospital at once .
两种说法都行,前者更好一些.