sign away . formally give up rights， property，money，by signing a document签字放弃（权利等）

He signed away his share of the house to his daughter．他签字把他那份房产让与女儿。

He later regretted that he signed away his right to his mother's estate．他后悔他签字放弃了继承他母亲遗产的权利。

 sign in . indicate one's arrival by signing a register签到

Teachers go to the office and sign in each morning before going to their classrooms．教师们每天早晨先到办公室签到，然后去教室上课。

sign off .  mark the end of a radio or television programme for the day结束广播

This is your favorite announcer signing off for tonight．这是你最喜欢的播音员在结束今晚的广播。

The local station signs off at midnight．地方台午夜停止广播。

sign off . end a letter结束书信

I must sign off now．Love，Mary．就止停笔。爱你的，玛丽。

sign off . stop work for the day停止工作

Because of the snow，we signed off at three o'clock．由于下雪，我们三点钟就下班了。

The man signed off work at half past six．那人在六点半下班。

sign on . sign an agreement to work for a company；join a team签约受雇

He signed on yesterday and will start work on Monday．他昨天签订了合同，星期一就要上班。

He signed on for another six years．他签约再工作六年。

sign on .  begin a radio programme for the day电台开始广播

The BBC signs on at six o'clock every morning．BBC广播每天早上六点开始广播。

sign on . register as unemployed at an office of the Department of Health and Social Security in Britain 在英国就业部地方办事处办理失业登记

When the steel works closed， a thousand men had to sign on ．当钢铁厂关闭时，一千名工人只得去办理失业登记手续。

sign out . indicate one's departure by signing a register签名登记离开

We signed out of college on Friday evening and returned on Monday morning．我们星期五晚上登记离校，星期一早上回校。

I'll sign them out and guarantee their good behavior．我给他们签字放行，保证他们行为端正。

 sign up . join by signing签约受雇；招收

Our factory signed up a number of young workers last week．上周我厂招收了一批青年工人。

 sign up . arrange a contact with跟…安排合同

They managed to sign up all the best performers．他们设法跟所有最佳演员签订了合同。

 similar to . like；resembling类似

His views are similar to mine．他的看法和我相似。

sing out . sing loudly大声唱

The children sang out lustily． 孩子们拉开嗓门使劲地唱。

sing out . call out loudly大声叫喊

If you need anything，just sing out and I'll come．如果你要什么的话，就大声喊我，我会来的。

The bell sang out the hour of midnight．钟声报出了午夜十二点。

 single out . select one person or thing from among many for special treatment 挑选出

We all did well，but the teacher singled him out for praise．我们都做得很好，但老师就表扬了他一个人。

He seems to have been singled out for all the nasty jobs． 他似乎是被挑出来专干脏活的。

I don't know why they keep singling me out for abuse? 我不知道他们为什么专喜欢骂我。

sink in . soak in . （cause to）sink into陷入；沉入

If the ink sinks in it'll be hard to remove the spot from the cloth．布一沾到墨水，墨迹就很难洗净。

sink in . soak in .  be absorbed， understood or acknowledged被充分理解或领会

I think it has finally sunk in that she must be more careful：she won't forget her passport again！我想她终于领悟到她必须更加小心，她再也不会忘了她的护照！

Everybody laughed at the joke but Joe；it took a moment for it to sink in before he laughed too．除了乔每个人都被这笑话逗乐了，过了一会儿他完全理解过来也笑了。

sit about . sit around . sit and do nothing懒洋洋地闲坐

She sat around all day and watched me clean the house．她整天闲坐着看我打扫房子。

Don't just sit about and dream！不要只是呆坐着梦想！

sit back . relax and do nothing休息

It is marvellous to be able to sit back after a day's hard work．一天辛劳工作后能坐下来休息休息真是太美妙了。

Get on with the work；this is not time to sit back．干活吧，这会儿可不是坐下来休息的时候。

sit back . be inactive；become a spectator 不采取行动；旁观

He's happy just to sit back and let others make the decision．他真乐意袖手旁观而让别人作决定。

Do you expect me to sit back and do nothing? 你希望我袖手旁观什么也不干吗?

sit by . stay near；watch and care for 守护照料

Mother sat by her sick baby all night．母亲通宵在生病的婴儿身边照料。

sit by . observe but fail to act as needed 袖手旁观

Even when his daughter was in trouble，he just sat by and did not help．即使他女儿陷入困境时，他也袖手旁观不予支援。

Don't just sit idly by while the other children are all busy．别的孩子都正忙着，你不要闲着什么也不干。