In 'come back', 'break down' and 'fall off', 'back', 'down' and 'off' are all adverbial particles.

在come back、break down和fall off中，back、down和off都是副词小词。

《牛津词典》

If it waits another fraction of a second, the force of gravity will overtake inertia, causing the column to break, the liquid to fall back into the bowl, and the cat's tongue to come up empty.

如果它再等上几分之一秒，重力的作用将压倒惯性而破坏液柱，液体会落回碗里，而小猫的舌头则扑了个空。

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Break up to do back to himself, a person's world also has a month to rise and fall, there is a beautiful moment, put him into memory.

分手了就做回自己，一个人的世界同样有月升月落，也有美丽的瞬间，把他归为记忆。

youdao

But Spanish ace Nadal kept battling and got a lucky break in the fourth game of the decider as his U.S opponent's return hit the net cord and bounced back on his side of the net to fall down a break.

CNN: Tennis: Nadal survives scare as Djokovic goes out