副詞 all at once:

1. all at the same time
   同義詞：all together
2. without warning
   同義詞：all of a sudden

1. All at once, a rabbit came out of a hole.
   突然，一只兔子從一個洞中跑了出來。
2. All at once the door opened.
   門突然打開了。
3. All at once she lost her temper.
   她突然發(fā)起脾氣來。
4. A wind arose, and rain drops began falling all at once.
   起風了，雨點忽然落下來。