1、private

（产业、服务）私立的，私有的，私营的，民营的

a joint venture with private industry.

与私营企业建立的合资企业

Bupa runs private hospitals in Britain.

保柏在英国开办私立医院。

个人的；私人的

the law's insistence that private citizens are not permitted to have weapons.

法律坚持要求公民个人不得持有武器

The King was on a private visit to enable him to pray at the tombs of his ancestors.

国王以私人身份出访，以便能够祭拜先祖陵墓。

（财物等）个人所有的，私有的，私人的

The landowners have had to sell their private aircraft.

这些土地所有者不得不卖掉自己的私人飞机。

They want more State control over private property.

他们希望加强国家对私有财产的控制。

2、necessary

必要的;必需的

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。

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。

(结果或联系)必然的，势必的

Wastage was no doubt a necessary consequence of war.

巨大的损耗无疑是战争的必然结果。

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。