This principle is called " herd immunity" .

这则被称为“群体免疫”。

For the first time, environmental principles will be enshrined in law.

环境保护则将首次写入法案。

Natural selection is the cornerstone principle of evolution.

物竞天择说是进化论的则。

I am conservative and I stick to my principles and keep to rules.

我是保守的人；我坚持则，遵规守矩。

As so often is the case, stating that principle doesn't ease the challenge of line-drawing.

即便如此规定，但也很难帮助我们做到泾渭分明，这事情也是时有发生。

It's my principles. We're talking about my principles.

这是则问题 重点是我的则。

The principle for taking samples is for it not to linger.

采集样本的则是不要逗留久。

But he was the first who ever did so by choice, out of principle.

但他确实是第个自愿这么做的人，这是出于他自己做人的则而已。

It challenges that most basic of principles of our international system - that borders cannot be redrawn at the barrel of a gun, that nations have the right to determine their own future.

俄罗斯挑战了我们的国际体系中最本的则——国境线不能通过枪炮来重新划定，国家有权决定自己的未来。

He's in it for the principle of creating sustainability and transport, as an ideology really.

他是为了创可持续交通方式的理念，这是他的理想。

In fact, “use it or lose it, ” is a principle that applies to much of biology – not just brains.

事实上，“使用它否则就失去它，”是适用于许多生物的理——不只是大脑。

The principle of British welfare is no longer that you can insure yourself against the risk of unemployment and receive unconditional payments if the disaster happens.

如果不幸的情况发生，英国的福利则不再是确保你自己避开失业的风险和无条件的接受失业保险。

To do otherwise would be against our core principles and our business interests.

否则将违背我们的核心则和我们的商业利益。

Oh, I didn't know that. What's the principle behind it?

我不知道这个。背后的理是什么？

Admittedly, education at school carries various virtues and serves to instill knowledge as well as moral principles in pupils.

诚然，学校的教育教授学生品德和知识，同样也教授小学生道德准则。

The principle of extracting raw silk hasn't changed since it's discovered.

抽取生丝的理，从发现至今并没什么改变。

Should we be alarmed by these accounts of falling standards of principles and morality?

我们该不该因这些关于行为准则和道德水准下降的报道而感到不安呢？

In Europe, parts of Italy, Greece, Portugal, Spain, and southern France adhere to principles of the Mediterranean diet, as do Morocco and Tunisia in North Africa.

在欧洲，意大利部分地区、希腊、葡萄牙、西班牙和法国南部坚持地中海饮食则，非洲北部的摩洛哥和突尼斯同样如此。

These commitments which companies will Implement immediately underscore three fundamental principles safety, security, and trust.

这些公司将立即履行的承诺强调了三个本则：安全、保障和信任。

You are always prepared to sacrifice your principles for a repartee, he answered.

“你为了反驳别人从来不怕牺牲自己的则。”他回答说。