on and off also off and on for short periods but not regularly over a long period of time断断续续地，间歇地:•He's been smoking for 10 years now, on and off.到现在，他断断续续地吸烟有十年了。 on and off intermittently 断断续续地： it rained on and off most of the afternoon. 下午大部分时间都在断断续续地下雨。 |