87>.all at once 突然
句子：
1.All at once it rained cats and dogs.
突然下起倾盆大雨．
2.All at once it rushed from the dark borizon toward the ship with a frightening speed.
突然它以惊人的速度从黑色的地平线冲向船只．
3.All at once the sky became dark and it started to rain.
突然天色变暗，开始下起雨来．
4.She cried her heart out all at once for the death of her pet.
她的宠物死了，她突然放声大哭起来．
5.All at once the horse bolted, and the rider fell off.
那匹马突然狂奔，所以骑士就摔了下来．
88>.off and on 偶尔；断断续续地
句子：
1.During the spring, it rains off and on here.
在春季，这里断断续续地下雨．
2.Mike has been working here off and on for five years.
迈克已断断续续地在这儿工作了5年．
3.She comes here off and on to see my father.
她偶尔来这儿探望我父亲．
4.They don’t go there often, just off and on.
他们不常去那里，只是偶尔去．
5.It has been raining off and on since noon.
从中午起就断断续续下着雨．
89.>once and for all 断然地；坚决地；仅此一次
句子：
1.I must tell you once and for all that I won’t marry you.
我必须坚定地告诉你，我不会嫁给你。
2.I told him once and for all that I wouldn’t go out with him any more .
我坚决得告诉他，不再和他出去了。
3.Once and for all, I told him I wouldn’t do it.
我断然地跟他说我不愿做这件事。
4.I will answer your question for once and for all.
我回答你的问题仅此一次。
5.Jane told Mark,once and for all,not to bother her any more.
简坚决地告诉马克不要再来打扰她。
90>.out of 相反；反面
句子：
1.He has been out of work for a long time.
他已经失业很久了。
2.I’m afraid that we are out of gas.
恐怕我们的汽油已经用完了。
3.The piano is out of tune.
这架钢琴的音不准。
4.This telephone is out of order.
这电话坏了。
5.All my clothes are out of date.
我所有的衣服都已过时