Sometimes it is necessary to say no.

有时候说“不”是必要的。

Repairs are necessary to strengthen the bridge.

这座桥需要加固。

For her, books were as necessary to life as bread.

对她来说，书就像面包一样是生活的必需。

It has been found necessary to make some cuts in the text.

已发现有必要对文章作些删节。

It is not always necessary to gut the fish prior to freezing.

在冷冻鱼之前没有必要总是取出其内脏。

They've been deprived of the fuel necessary to heat their homes.

他们无法得到住房取暖必需的燃料。

It may also be necessary to get a new appraisal of the property.

可能还需要对该房产做个新的估价。

It is always necessary to have regard to the terms of the contract.

记住合同条款总是必要的。

He had the ruthless streak necessary to carry him into the cabinet.

他有着跻身内阁所必需的冷酷品性。

I kept the engine running because it might be necessary to leave fast.

我让发动机一直开着，因为可能需要快速离开。

To understand why they are doing it, it is necessary to know where they are coming from.

要理解他们为什么这样做，有必要知道他们的想法。

It's necessary to bring a gift.

带礼物是有必要的。

It's very necessary to use public chopsticks more.

多使用公筷是很有必要的。

It's necessary to follow the rules in any games.

在任何游戏中，遵守规则都是必要的。

It's necessary to wear the mask in the groups of people.

在人群中戴口罩是必要的。

It's necessary to pick up rubbish and put it into dustbin.

拾起垃圾，把它放进垃圾箱是必要的。

I don't think it's necessary to start so early.

我认为没有必要这么早就开始。

It is no longer necessary to dress like everyone else.

没必要穿得和别人一样。

It is not necessary to enroll before the course starts.

不需要在课程开始前注册。

It is not necessary to set down the rest of the oration.

没有必要把这篇演说的其余部分写下来。

At the outset, it seemed necessary to be on guard against the other two.

一开始，似乎有必要提防另外两个。

It appears necessary to learn something useful to protect the family from them.

学习一些有用的东西来保护家庭免受它们的伤害似乎是很有必要的。

It isn't necessary to know anything about sailing—students can learn on the ship.

没有必要知道任何有关航海的知识——学生们可以在船上学到。

It may be necessary to buy a new one.

也许有必要买个新的了。

She found it necessary to reassert her position.

她觉得有必要重申她的立场。

It is necessary to examine how the proposals can be carried out.

有必要调查一下怎样才能实施这些方案。

Vitamin D is necessary to aid the absorption of calcium from food.

从食物中吸取钙需靠维生素D的帮助。

It might be necessary to make a few slight modifications to the design.

也许有必要对这个设计稍作几处修改。

It was necessary to discover the truth or otherwise of these statements.

有必要查证这些说法的真实性或虚假性。

She had resumed the travel necessary to add depth and colour to her novels.

她重新开始旅行以给她的小说增加深度和趣味。