persist in . continue resolutely继续 ；坚持
She persisted in wearing that old fashioned hat．她坚持要戴那顶旧式的帽子。
He persisted in carrying on his work in spite of great fatigue．他虽然疲倦极了，可是仍然坚持工作。
persuade of . convince 使相信
How can I persuade you of my sincerity? 我如何才能使你相信我是真诚的呢?
I am persuaded of his honesty．我相信他是诚实的。
pertain to . be connected or associated with something 从属；附属
The fire and dash pertaining to youth are not much in evidence among these people．年轻人固有的热情和锐气在这些人身上不很明显。
The other questions pertaining to this matter have yet to be answered．关于这事的其它问题还有待于回答。
We have got the documents pertaining to the case．我们已经得到了该案件的有关文件。
peter out . steadily weaken or decrease and come to an end渐趋消失；逐渐停止
Her enthusiasm for dancing petered out and she stopped going to lessons．她对舞蹈的热情已渐趋消失，而且已不再去上课了。
The enemy's supplies petered out．敌人的给养耗尽了。
As he thought of her， his anger slowly petered out．一想到她，他的怒气就慢慢平息了。
phase in . introduce something gradually or in stage 逐步采用；分阶段引入
They phased in the new course by accepting just five students in the first year， and ten in the second．他们逐步发展新专业，第一年只收5个学生，第二年收了十个学生。
They've decided to phase the new techniques in．他们已决定逐步引进那些新技术。
phase out . withdraw something gradually or in stage逐步停止；逐步撤去；逐步淘汰
Will that country phase out its oil exports? 那个国家会逐步停止输出石油吗?
The agreement called for the phasing out of troops in the area．协议要求从那个地区逐步撤出军队。
The old machinery here will be phased out．这里的旧机器将被逐步淘汰。
pick and choose . select with much care挑三拣四
Some people pick and choose to get something perfect，and some just because they can't make up their minds．有些人挑剔是想得到完美的东西，而有的人只是因为拿不定主意。
You haven't time to pick and choose from among so many pictures．这么多的图片，你是没有时间从中细选的。
pick apart . tear into pieces . 撕成碎片；拆散
As this skirt fits badly，I'll pick it apart and remake it ．这条裙子不合身，我要把它拆了重做。
pick apart .criticize harshly；find fault with 猛烈批评；找岔子
He is always picking apart every girl he meets．Naturally everyone has some faults．他每遇到一个姑娘总爱挑剔，其实每个人都会有缺点的。
After the dance， the girls picked Mary apart．舞会后，女孩们都责备玛丽。
pick at . eat without appetite挑食
Stop picking at your food， Janet！
Eat it all up or you won't have any pudding！珍妮，不要挑食！全部吃下去，否则就不给你吃布丁了！
She had no appetite and only picked at food．她食欲不振，只吃了一点点食物。
pick at . find fault with对…吹毛求疵
They showed their displeasure by continually picking at her．他们不断挑她的毛病以示他们的不满。
She'd been picked at so often by parents and teachers that she didn't know how to behave．家长和老师经常对她吹毛求疵，她简直不知怎么办才好。
pick off . take off； remove with the fingers脱下
The insecticide might harm the flowers Let's pick off the insects by hand．杀虫剂可能会伤害花朵。我们还是用手把虫捉下来吧。
Don't pick off any of these flowers．这些花一朵也不要摘。
pick off . shoot or bring down singly or selectively逐个地或有选择地射中或打下
They picked off the officers first，so as to throw the enemy troops into confusion．他们首先把军官一个个地击毙，使敌军陷入混乱。
pick on . annoy使烦恼
The children picked their father on until he agreed to have a ride．孩子们一直缠着父亲，直到他同意开车出去兜风。
Little Tom complained that his mother was always picking on him．小汤姆抱怨说，妈妈老是挑他毛病。
pick on . choose选择
He visited a lot of universities，and finally picked on Stanford．他去了许多大学，最后选择了斯坦福大学。
Why do they always pick on her to do the difficult tasks? 他们为什么老是找她去干困难的工作?
pick one's way . advance with care谨慎前进
After nightfall we drove slowly along，picking our way until we found the right building．天黑后，我们驾车慢慢地往前开，直到发现了我们要找的大楼。
The driver picked his way across the rough and rocky hillside．司机小心地越过崎岖的山坡。
pick out . choose挑选
It took Mary a long time to pick out a new dress at the store．玛丽在商店里花了好长时间才挑中一件新衣服。
You may pick out any two books listed here．你可以在这图书目录中任选两本。
pick out . tell from others区分
We could pick out different places in the city from the airplane．从飞机上我们可以辨认出这座城市里的不同地方。
Although he had not seen his sister for twenty years，he picked her out as soon as she got off the plane．尽管他和妹妹有二十年没见了，可她一下飞机他就认出了她。
He has such a distinctive appearance that I could pick him out anywhere．他的样子非常特别，不论在哪里我都可以认出他来。
pick out . tell the meaning领会；弄明白
In spite of the difficulty of the passage，we succeeded in picking out its sense by our concerted efforts．这段文字虽然难懂，但我们通过共同努力还是弄懂了它的含义。
pick out . play a tune by ear on a musical instrument凭听觉记忆在乐器上奏出曲调
As soon as she'd sung the first verse， he picked out the tune on the piano．她一唱完第一部分，他就在钢琴上把它弹奏了出来。
pick out . relieve（the ground color）with another color（用不同的颜色）衬托（底色）
The ancient cloister was a structure of red brick picked out with white stones．这个古老的修道院是一座白石衬托红砖的建筑物。
All the important passages in the article were picked out in red．该文的重要段落均用红笔勾出。