马甲和他的同行们会对他们知道的一些所谓“零天漏洞”——即软件缺陷——保密，以备将来使用。

Majia and his fellow hackers keep secret their knowledgeof certain so-called zero-day vulnerabilities — software flaws — forfuture use, he says.

youdao

该漏洞被称为“零日”漏洞，因为这一漏洞自从产品推出以来就一直存在——从第“零天”开始就存在，甚至连开发人员都没有发现过。

It is known as a "zero-day" vulnerability because, effectively, it has been there since the product was launched - day zero - and not even its developer had spotted it.

youdao

这是晚冬晴朗的一天，只有零上几度。

It's a sunny late winter day, just a few degrees above zero.

《柯林斯英汉双解大词典》