necessary

adj.

1. 必需的；必要的
   that is needed for a purpose or a reason
   1. It may be necessary to buy a new one.
      也许有必要买个新的了。
   2. It doesn't seem necessary for us to meet.
      我们似乎没必要见面。
   3. Only use your car when absolutely necessary.
      非用不可的时候再用你的汽车。
   4. If necessary , you can contact me at home.
      必要的话，我在家时你也可以和我联系。
   5. I'll make the necessary arrangements.
      我会做一些必要的安排。
2. 必然的；无法避免的
   that must exist or happen and cannot be avoided
   1. This is a necessary consequence of progress.
      这是发展的必然后果。

1. ADJ-GRADED 必要的;必需的
   Something that is necessary is needed in order for something else to happen.
   1. I kept the engine running because it might be necessary to leave fast...
      我没让发动机熄火，因为也许需要迅速离开。
   2. We will do whatever is necessary to stop them...
      我们要采取一切必要措施去阻止他们。
   3. Is that really necessary?...
      那真有必要吗？
   4. Make the necessary arrangements.
      做一下必要的安排。
2. ADJ (结果或联系)必然的，势必的
   A necessary consequence or connection must happen or exist, because of the nature of the things or events involved.
   1. Wastage was no doubt a necessary consequence of war...
      巨大的损耗无疑是战争的必然结果。
   2. Scientific work is differentiated from art by its necessary connection with the idea of progress.
      科学工作与艺术的区别在于它与人类进步有着必然联系。
3. N-PLURAL 基本生活必需;必需品
   Necessaries are things, such as food or clothing, that you need to have in order to live.
   1. ...a small parcel of necessaries tied up in a handkerchief and carried on a stick.
      用手绢包好挑在棍子上的一小包生活必需品
4. PHRASE 如果必要的话
   If you say that something will happen if necessary ,when necessary, or where necessary, you mean that it will happen if it is necessary, when it is necessary, or where it is necessary.
   1. If necessary, the airship can stay up there for days to keep out of danger...
      必要时，飞艇能在那里停留数天以躲避危险。
   2. The army needs men who are willing to fight, when necessary...
      军队需要在必要时愿意投入战斗的军人。
   3. All the rigging had been examined, and renewed where necessary.
      所有索具都进行了检查，并把该更换的部件全部更换一新。

Be careful with the spelling of this word.
注意该词的拼写。

1. The ministry said it reserved the right to take whatever action necessary.
   该部表示保留采取任何必要行动的权利。
2. If you are agreeable, my husband's office will make all the necessary arrangements.
   如果你同意，我丈夫的事务所将作出所有必要的安排。
3. And let me assure you I will use whatever force is necessary to restore order.
   我向你保证，我将动用一切必要力量来恢复秩序。
4. We are willing to authorize the president to use force if necessary.
   我们愿意授权总统在必要的时候使用武力。
5. It's only necessary to use just a very small blob.
   只需要很小的一滴就可以了。
6. She had resumed the travel necessary to add depth and colour to her novels.
   她重新开始了旅行，那是增加自己小说的深度和趣味性所必不可少的。
7. Political knowledge is a necessary complement to science in approaching solutions to these problems.
   在寻找解决这些问题的方法时，需要有政治知识作为对科学知识的补充。
8. To improve the quality of life through work, two complementary strategies are necessary
   想通过工作提高生活质量，需要两个相辅相成的策略。
9. He says he would support the use of force if the UN deemed it necessary
   他说如果联合国认为有必要使用武力，他将予以支持。
10. An active and expansive market economy is a necessary condition for progress.
    积极扩张的市场经济是发展的必要条件。
11. All the necessary conditions were fulfilled.
    所有必要的条件都满足了。
12. They believe that a fundamental change in the governance of Britain is the key to all other necessary changes.
    他们认为从根本上改变英国的统治方式是促成其他所有必要变革的关键所在。
13. I kept the engine running because it might be necessary to leave fast
    我没让发动机熄火，因为也许需要迅速离开。
14. We will do whatever is necessary to stop them
    我们要采取一切必要措施去阻止他们。
15. Is that really necessary?
    那真有必要吗？
16. Make the necessary arrangements.
    做一下必要的安排。
17. Wastage was no doubt a necessary consequence of war
    巨大的损耗无疑是战争的必然结果。
18. Scientific work is differentiated from art by its necessary connection with the idea of progress.
    科学工作与艺术的区别在于它与人类进步有着必然联系。
19. If necessary, the airship can stay up there for days to keep out of danger
    必要时，飞艇能在那里停留数天以躲避危险。
20. The army needs men who are willing to fight, when necessary
    军队需要在必要时愿意投入战斗的军人。
21. All the rigging had been examined, and renewed where necessary.
    所有索具都进行了检查，并把该更换的部件全部更换一新。
22. Protective measures are necessary if the city's monuments are to be preserved.
    要保存城市古迹必须采取一些维护性措施。
23. A clearly quantifiable measure of quality is not necessary.
    没有必要对质量进行明确的定量测量。
24. The government has reaffirmed that it will take any steps necessary to maintain law and order.
    政府重申将采取一切必要措施维护法律和秩序。
25. Discipline is a necessary, but certainly not a sufficient condition for learning to take place.
    纪律是有必要的，但绝对不是保证学习成效的充分条件。
26. If necessary X-rays and blood tests will also be used to aid diagnosis
    如有必要，还要进行X光检查和验血以帮助诊断。
27. A command of information is the necessary prerequisite to the scientific consideration of any subject.
    掌握资料是科学地思考任何问题的必要的先决条件。
28. We consulted the original and made some necessary changes.
    我们参照原文作了必要的修改。
29. These reference books are necessary to us.
    这些参考书是我们所必需的。
30. The delegation deems it necessary to state its position.
    代表团认为有必要说明自己的立场。

  necessary compulsory【导航词义：必要的】

  necessary adj. 必需的，必要的

〔辨析〕普通用词，多指由客观因素决定的，是必不可少的。

  compulsory adj. 必须做的，规定的，义务的

〔辨析〕指由法律、上级命令等规定或强制的。

adj.

a necessary evil

• 无法避免的坏事；不得已的事
  a thing that is bad or that you do not like but which you must accept for a particular reason

noun

1. anything indispensable
   1. food and shelter are necessities of life
   2. the essentials of the good life
   3. allow farmers to buy their requirements under favorable conditions
   4. a place where the requisites of water fuel and fodder can be obtained

   Synonym:    necessityessentialrequirementrequisite

adj

1. unavoidably determined by prior circumstances
   1. the necessary consequences of one's actions

2. absolutely essential