all at once
例
The lights went out all at once, leaving the room in darkness.
明かりが突然消え、部屋は暗闇に包まれた。
All at once, the crowd began cheering as the band took the stage.
突然、バンドがステージに上がると、群衆は歓声を上げ始めた。
例
The children started talking all at once, making it hard to hear anyone.
子供たちが一斉に話し始め、誰の声も聞き取りにくくなった。
The lights went out all at once, plunging the room into darkness.
明かりが突然消え、部屋は暗闇に包まれた。
