On and off for about three years.

断断续续差不多三年。

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

他断断续续75年的时间。

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

“1”和“0”代表晶体管的开关状态。

It's politically unstable and it's dealt with on and off conflict for years.

它的政治不稳，多年来一直在处理冲突事件。

These are young people who are making impressions and differences on and off the field.

这些年轻人在场上和场外都留下深刻的印象。

Some have been closed on and off as cases of COVID have come and gone.

随着新冠肺炎病例的出现和消失，有些陆陆续续地关闭。

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

最后，她说，I was teaching on and off。

Oh, about two years on and off.

断断续续有两年。

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.

时器可以为你时开关电灯。

I started taking medication on and off, and well, it was pretty obvious.

我开始只有偶尔才吃药， 嗯，这挺明显的。

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

另外，它们非常容易开关。

In the following years, climate change slipped on and off the global agenda.

在接下来的几年里，气候变化问题在全球议程上忽上忽下。

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

我断断续续在这里住九年。

Sparks were emitted from small black boxes and red lamps flashed on and off angrily.

小黑盒子里迸出火花，红色灯泡发怒似地忽明忽暗。

Many people flicked their headlights on and off, bathing me in a stuttery glow.

许多人把车头灯闪又灭，将我笼罩在明灭的光照里。

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

此后，他经历当选、连任失败和再次当选。

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

它可以打开和关闭你家里的灯光。

A small timer microprocessor turns the pumps on and off.

一个小型时微处理器打开和关闭泵。

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

不是你的意愿能够控制。