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》

We'll be back after the break with a round-up of today's other stories.

休息之后我们会摘要报道今天其他的新闻。

《牛津词典》

She held back, not knowing how to break the terrible news.

她踌躇着，不知如何说出这一可怕的消息。

《牛津词典》

Take your time. So, let's actually now take a 2-minute break, we're gonna change tapes and we'll come back and we'll actually write programs with a real computer and some real animated characters.

不急，现在休息2分钟，我们要换个录像带，一会再上课,等会开始写程序,构建一些动画人物。

哈佛公开课 - 计算机科学课程节选

Murray, 23, squandered a gilt-edged break-back opportunity at 3-4 and found himself serving to stay in the set in the following game, but held to force his 29-year-old opponent to serve it out.

BBC: Andy Murray into last eight of China Open in Beijing

Nadal stepped up a gear to break back at 5-3 before taking it on a tie-break and one break was enough in the third.

BBC: Nadal win sets up Federer final

Four minutes later a length-of-the-field break by full-back Morgan Stoddart put winger Jones in to outpace Beauxis from outside the 22 to put his side 8-6 up.

BBC: Stade Francais 37-15 Scarlets