ignorant of . （of person） knowing little or nothing about；not aware of无知识的；不知道的
I am completely ignorant of his intentions．我对他的企图全然不知。
He is ignorant of English．他不懂英语。
He was ignorant of the fact．他不了解事实。
in hand . available for use（手头）有；现有的；可支配的
I still have some money in hand．我手头还有些钱。
Tom figured that his cash in hand with his weekly pay would be enough to buy a car．汤姆算了一下，他手头的钱加上周薪够买车了。
I have only got ten minutes left in hand，so I must conclude my talk with a brief summary．我只有十分钟了，因此我只能简单地归纳一下来结束我的讲话。
in hand . in process；being worked on在进行中
The work is in hand，but not finished．工作在进行中，还没完成。
We should finish the work we have in hand before we begin something new．在开始新工作之前，我们应先完成正在做的工作。
in hand . under control控制
The principal was happy to find that the new teacher had her class in hand．校长高兴地发现新老师已将她的班级管理好了。
The police now have the situation well in hand， and no further outbreaks are expected．警方现在已经控制了局面，不会再有什么事情发生。
ill at ease . not feeling at ease or comfortable ；anxious；worried；unhappy紧张不安；焦虑；不愉快
This made me ill at ease．这使我局促不安。
When she first went to the dancing school， she was ill at ease，not knowing what to do．当她第一天到舞蹈学校时，紧张得不知所措。
at the news he seemed ill at ease．听到这消息他似乎显得不安。
immerse in . involve deeply陷入；埋头于
He is immersed in the study of English．他潜心攻读英语。
Though they were immersed in difficulties，they were still in high spirits．虽然他们陷于重重困难， 但仍然情绪高涨。
He immersed himself in sorrow． 他陷于悲伤之中。
immerse in . put under the surface of,（water or other liquid）浸入
She immersed her head in the water.她把头浸入水中。
impose on . impose upon . place（a tax，duty，） on,把 （税、任务等）加到…上
I must per form the task that has been imposed upon me．我必须完 成我所承担的任务。
New duties were imposed on wines and spirits．酒类被加征新税。
impose on . impose upon . force…on；force the acceptance of,强加；强迫…接受
Don't try to impose your wishes on us．不要企图把你的意志强加到 我们头上。
He imposed his opinion on me.他 把他的意见强加于我。
impose on . impose upon . deceive；cheat； trick欺骗
We are not to be imposed upon．我 们是不会上当的。
He was too wise to be imposed upon by fair words spoken without sincerity．他很聪明，不会被花言巧 语所骗。
impose on . impose upon . try to get more than offered要 求过份；得寸进尺；利用
Don't you think you are imposing on your neighbor when you use his telephone for half an hour? 邻居 的电话你一用就是半个小时，你 不觉得太过份了吗?
improve on . make better改进；改善；改良
I am unable to improve on his suggestion．我提不出比他更好的建 议了。
This method is better，but can still be improved upon．这个方法是好 多了，但还可以改进。
She made good marks the first year，but she thought she could improve on them．她第一年成绩很 好，但她认为还可以更好。
in demand . in great demand . much sought after大量需要
The goods are much in demand in winter．这种物品冬季需求量很大。
Oil is in great demand these days．现在非常需要石油。
in course of time . in the progress of time迟早；终有一日
If you study hard， you'll learn English well in course of time．如果你努力学习，最终你一定能掌握英语。
in course of . in the course of .in process of；during the process or progress of正在…之中
The railway is now in course of construction．那条铁路正在建造之中。
He happened，in course of conversation，to say that he had the intention of visiting China．在谈话中，他碰巧提到他有意访问中国。
in face of . in the face of . confronted by . 面对
He never shows any fear in face of danger．在危险面前他从不畏惧。
What could he do in face of all these difficulties? 面对这些困难，他能干什么呢?
in face of . in the face of . in opposition to；in spite of反对；不顾
Talking continued even in the face of the teacher's command to stop．纵然老师已下令停止谈话，但有人还是讲个不停。
He succeeded in the face of all difficulties．尽管困难重重，他还是成功了。
in light of . in the light of . because of由于；因为
In light of the muddy field， the football team put on their rubbers．因为道路泥泞，足球队员都穿上了胶鞋。
in light of . in the light of . according to；as a result of （new information）； by means of （new idea）依据；根据
It is to be regarded as excusable in the light of circumstance．考虑到具体情况，这将被看作是可以原谅的。
The teacher changed John's grade in the light of the extra work in his exercise book．老师根据他作业本里所做的额外作业而更改了他的成绩。