注释采用牛津字典（其中第一，二义最重要，要想快点进步，建议多看英英解释）

7.<mark>dilemma , struggle , collision , paradox</mark>

简明：

  1. <mark>dilemma：表示进退两难的境地</mark>
  2. <mark>struggle：努力去面对困难和挑战</mark>
  3. <mark>collision：物体的相撞；两个人的冲突；对立观点，想法的冲突</mark>
  4. <mark>paradox：自相矛盾的结论</mark>

题目：

We work to make money , but it’s a ____ that people who work hard and long often do not make the most money.（D）

A.dilemma B.struggle C.collision D.paradox

dilemma：（n）

1。a situation which makes problems , often one in which you have to make a vary difficult chioce between things of equal importance
（进退两难的）窘境，困难

例句：

 1. to face  a dilemma.  面临左右为难的困境
 2. to be in a dilemma.   处于进退两难的境地
 3. They were caught in a real dilemma.   他们陷入了进退两难的境地

struggle：（v）（n）

（v）
1。~ (for sth) to try very hard to do sth when it is difficult or when there are a lot of problems.
奋斗；努力；争取

2。to move somewhere or do sth with difficulty
艰难地进行；吃力的进行

例句：

 1. I struggled up the hill with the heavy bags.  我背着几个沉重的包吃力地爬上去。

3。~ （ against / with sb/ sth）to fight against sb / sth order to prevent a bad situation or reault
斗争；抗争

（n）
1。~ （with sb) (for / against sth) | ~(with sb) (to do sth) | ~ (between A and B)
a hard fight in which people try to obtain or achieve sth , especially sth that sb else does not want them to have
斗争；奋斗；努力

例句：

 1. a power / leadership struggle. 权力的争夺。
 2. It was a hard struggle to get my work done in time. 为使工作按时完成，我做了一番努力。

collision：（n）

~ (with sb / sth) | ~ (between / of A and B)
1。an accident in which two vehicles or people crash into each other
碰撞事故

例句：

 1. a collision between two trains. 两列火车相撞事故。

2。a strong disagreement betweenn two people or between oppposing ideas , opinions , etc;the meeting of two things that are very different.
（两人之或对立意见、看法等之间的）冲突，抵触

例句：

 1. a collision between two opposing points of view. 两种对立观点的冲突

paradox：（n）

1。a person , thing or situation that has two opposite features and therefore seems strange.
矛盾的人（或情况、事务）

2。a statement containing two opposite ideas that make it seem impossible or unlikely , although it is probably true ; the use of this in writing.
自相矛盾的结论