查询词典 have trouble doing sth.

He asked me for a meal and a glass of beer. ask for sth =request for sth.

问某人要什么东西（for为了这个目的去请求某人， sb。

Ask sb. for sth./ask sth.of sb.

向某人要求某物

Ask sth. of sb.- ask sb. for sth., request

向某人要东西，请求得到

It's important to be polite and considerate .for example,when we ask for sth,we should say,"please",and when we receive sth,we should say,"thank you".

我们与人相处时要有礼貌并估计他人的感受，比如说：要求他人帮忙时，应该说"请"，别人帮了自己时应该说"谢谢"。

Assist at/in sth;Be present at or take part in sth

在某场合出席；参加某事物

At the expense of sth.: with loss or damage to sth.

在损失或损坏某事物的情况下

Attach sth. to sth.

在…上贴上标签 28。

Mean to do sth.＝intend/plan/attempt to do sth.

误了两天的课，这不像她的行为。

Attempt to do sth.=try to do sth.

尝试做某事不一定获得成功

Make an attempt at sth／to do sth.

企图做某事

In other research, chondroitin is being investigated for use in several other conditions.

在其它研究，软骨素被调查用於几个其它情况。

They would make fun of him for having to work.

他们拿他的工作来开玩笑。