必须的

"It's an operation that needs to be done, it's the cruciate as everyone knows, and to be honest, I'm looking forward to it because it is a chink of light for me."

"这次手术是必须的，每个人都知道是十字韧带，老实说，我期待它因为那是我的希望。"

Also developed the calculus which is necessary to perform the mathematical calculations involved in classical mechanics.

牛頓也发展了微积分，那对经典力学的数学计算是必须的。

If you'd like to excel in conversation, knowledge of the classics is essential.

如果你想在谈话中优于他人，经典名著的知识是必须的。

We give people an opportunity to give every week, but this is not compulsory.

每星期我们有奉献的时间但这不是必须的。

Effectivity . This Agreement shall take effect and be binding on Company A and Company B only upon Company A and Company B's execution and delivery of this Agreement to the Concessionaire.

参考译文：生效本协议仅得于公司 A 和公司 B 根据适用法律规定取得必须的ZF批准，签署本协议并将经正式签署的协议副本交付"特许经营公司"后方可生效，并对公司 A 和公司 B 产生约束力。

Effectivity .This Agreement shall take effect and be binding on Company A and Company B only upon Company A and Company B's execution and delivery of this Agreement to the Concessionaire.

本协议仅得于公司 A 和公司 B 根据适用法律规定取得必须的政府批准，签署本协议并将经正式签署的协议副本交付"特许经营公司"后方可生效，并对公司 A 和公司 B 产生约束力。

Parentheses are not necessary around the first expression of a conditional expression, since the precedence of ?

条件表达式中第一个表达式两边的圆括号并不是必须的，这是因为条件运算符？

But if you want to be successful in the longrun, consistency is a must.

但是如果你关注博客的长期成功，则持续性是必须的。

The two functions represent a layer of indirection which is necessary to support classes that are not Copy Constructible by default.

这两个函数表示为一个间接层，为了支持缺省为不可复制构造的类，这是必须的。

Roulette, which means small wheel in French, is a casino and gambling game where a croupier rolls a ball and turns a round roulette wheel which has 37 or 38 separately numbered pockets in which a ball must land.

轮盘赌，这意味著小四轮在法国，是一个赌场，赌博等游戏croupier如卷一个球，并轮流一次轮盘赌有37或38条单独编号的口袋，其中一个球必须的土地。

I can not make it blossom and suits me

我不能让树为我开花

When temperatures are above approximately 80 °C discolouration of the raceways or rolling elements is a frequent feature.

当温度高于 80 °C 左右时，滚道或滚动元件褪色是很常见的特征。