boast of . boast about . talk proudly about自夸；炫耀
He always boasts of his learning．他常常夸耀自己的学识。
A wise man never boasts of his knowledge．聪明人从不自夸有学问。
boil down . be reduced by boiling煮浓
These apples will soon boil down to jelly．这些苹果不久就会煮成果酱了。
boil down .；mean；summarize 意味着；归结为；使缩短
You can boil down the story to a few sentences．你可以用几句话来概括这个故事。
What the foreign minister said boiled down to the rejection of the proposal．外交部长的话意味着拒绝这项建议。
The whole discussion boils down to the question of whether the government should fix prices．整个讨论归结到政府是否应当规定价格。
boil over . overflow by boiling煮沸溢出
Turn off the gas．The milk is boiling over．关上煤气，牛奶溢出来了。
book down . register登记下来
Every sum of money paid or received must be booked down immediately．支出或收入的每一笔款都必须立即记账。
Detailed items of all the goods to be shipped have to be booked down．待运货物的细目必须登记下来。
book in .report one's arrival；reserve a place for 登记；为…预订住处
Immediately on arrival at the office，all employees have to book in．所有职员一到办公室就必须登记签到。
I booked you in at that hotel．我为你在那家旅店订了房间。
book up . make reservations of ；be engaged previously预定座位、车船票等
It is always advisable to book up as far in advance as possible，especially in the rush．尤其是旺季，最好要尽可能地提前预定车船票。
The theater is booked up for every evening this week except Friday．除了星期五外，这个剧院本周的晚场票都预定完了。
border on . border upon . be next to；come close to接近；毗邻
China borders on Mongolia to the north．中国的北方同蒙古接邻。
born of . owing origin to；owing existence to 出身于；源于
born of the same parents .胞；同胞
Born of the same parents he bears no resemblance to his brother. 虽然是同一父母所生，他和他的弟弟毫无相似之处。
She was born of Russian parents．她的父母是俄国人。
bottle up . restrain 抑制（愤怒、感情等）
There was no understanding person to talk to，so he bottled up his unhappy feelings．既然没有可以相互理解的人谈心里话，他只好把不悦之情闷在心里。
The tension in the family is caused by everyone bottling up their feelings．家庭的紧张关系是因为大家把不悦之情闷在心里所造成的。
Don't bottle it up；speak out．不要闷在心里，都说出来。
bottle up . entrap；enclose 使陷入困境；包围
Our warships bottled up the enemy fleet in the harbour．我们的舰队把敌舰封锁在港内。
The enemy was bottled up like turtles in a jar．敌人被围困得象瓮中之鳖。
bound for . going in the direction of 开往；驶向
The ship is bound for Wuhan．这船是开往武汉的。
bound for . intending to go to准备到…去
Where are they bound for？他们要到哪里去？
They are bound for Northeast China to clear the wild land．他们正准备去东北开垦荒原。
bound to . under the obligation；obliged有义务的；受到约束的
We are bound to help them overcome the difficulties．我们有义务帮助他们克服困难。
bound to . sure to；determined to 一定的；决心要
Are you bound to stay at the office so late？你必须在办公室呆到这么晚吗？
The girl is bound to win a prize medal．这女孩决心要获得奖章。
Under the leadership of the Party，the Chinese people are bound to win the victory．在党的领导下，中国人民必定取得胜利。
He is bound to succeed in doing the experiment．他一定会试验成功。
bound to . destined for驶往
She stood on the seaside，watching the ships bound to distant lands．她站在海边，目送船舶驶向遥远的国度。
bound up in . busy with；deeply concerned with 热心于；关注于
They are bound up in the difficult task．他们的全部身心都投入这项艰难的工作中了。
He is bound up in his wife and children．他埋头于自己的小家庭。
bound up with . have a very close connection with 同…密切相关
The affair was bound up with their interests．这件事同他们的利益密切相关。
The welfare of the individual is bound up with the welfare of the community．个人福利与社会福利息息相关。
bow down .weigh down；cause something to bend 压弯
The apple tree is bowed down with the weight of its fruit．果实累累，压弯了苹果树。
bow down .cause somebody to suffer 使…遭受；使…受折磨
On hearing of her father's death she was bowed down with grief．接到父亲去世的噩耗，她悲痛万分。
He was bowed down with troubles．他困难重重，精神不振。
bow down .admit defeat；give way；make somebody yield to 认输；低头；使某人屈服
He has always refused to bow down to tyranny，wealth or power．他从来没有向暴政、财富或权力低过头。