So there are still key links in this mystery that are missing.

因此，这一谜团中仍有一些关键环节缺失。

By disrupting a key link in the food chain, we could be changing our entire way of life.

通过破坏食物链中的一个关键环节，我们可能会改变我们的整个生活方式。

Ask the app to issue a new key linked to your friend's phone—and just text or email it.

在应用里重新生成一个密钥，并链接到你朋友的手机上——发短信或者邮件即可。

Hodeida is a key link in the effort to ship food aid into Yemen where millions of people are threatened by starvation.

荷台达是将救援食物送往也门地区的关键节点，在也门有数百万人正受到饥饿的威胁。