On and off for about three years.

断断差不多三年了。

He studied for his degree on and off for 75 years.

他断断学习了75年的时间。

The car engine goes on and off?

就凭汽车发动又停下？

The bird's lights blink on and off.

这个燕子标志灯一闪一闪的。

A timer turns your lights on and off.

定时器可以为你定时开关电灯。

Ones and zeroes representing the on and off states of the transistor.

“1”“0”代表晶体管的开关状态。

So I was teaching on and off for several years.

我断断教了几年书。

Plus, they're super easy to toggle on and off.

另外，它们非常容易开关。

A small timer microprocessor turns the pumps on and off.

一个小型定时微处理器打开关闭泵。

I've been living here on and off for nine years.

我断断在这里住了九年。

He's served on, and off, and on again since then.

此后，他经历了当选、连任失败再次当选。

It can turn the lights in your home on and off.

它可以打开关闭你家里的灯光。

You can't turn it on and off whenever you want.

不是你的意愿能够控制。

Did it move or do they just blink on and off?

它动了吗？还是它们只是忽明忽暗？

There's switches so you can turn things on and off.

驱动器还有开关， 让你能够实现启动关闭功能。

The past few years have been spent on and off anti-depressants.

过去的几年里，他一直在断断服用抗抑郁药物。

And finally, here she says that, " I was teaching on and off."

最后，她说，I was teaching on and off。

" It doesn't just turn the lights on and off, " said Ron.

“它的作用并不只是开灯关灯，”罗恩说道。

On and off travel restrictions were in place between the two nations.

很多方都曾被两国曾列为旅行限制。

Were you guys together a long time? -A year, on and off.

你们在一起很久了吗？ -一年了，总是分分合合的。