all at once和all of a sudden均有“突然”的意思,不过前者还有同时的意思.如：When I asked a question,he put up his hand all at once.(我一提问,她立刻就举起手) When I asked a question,she shouted all of a sudden.（当我提问时,她突然喊了起来）
all of a sudden和all at once的区别?大神们帮帮忙
all at once和all of a sudden均有“突然”的意思,不过前者还有同时的意思.如：When I asked a question,he put up his hand all at once.(我一提问,她立刻就举起手) When I asked a question,she shouted all of a sudden.（当我提问时,她突然喊了起来）