<b>on and off</b><b></b><br>
<b>断断续续的</b>
On and off 可不是“又开又关”哦！那是什么意思呢？当我们说on and off，表示的是做某事断断续续。
<b>●</b><b>例句●</b>
It's been raining<b>on and off</b>all morning.
雨断断续续地下了一早上。<br>
He's been learning English for 3 years now,<b>on andoff</b>.
他断断续续地学了3年英语了。