“你在生活中做的所有事都必须是安全的，我今天所做的也是如此。”他说道。

"You've got to do everything safe in life, and that's what I did today," he said.

youdao

核能是清洁的，也必须是安全的。

Nuclear energy is clean, and it must also be safe and secure.

youdao

当然，部署必须是安全的。

Of course, deployment must be secured.

youdao

Anybody who's envolved in this area has to know the president cares most about keeping the country safe.

所有有关的人,必须知道总统最重视的是,保卫国家安全。

普林斯顿公开课 - 国际座谈会课程节选

So they have to be engineered to be inert so that they can be safely inside a system and there's not every material you could pick would have that property.

缝合线必须是惰性的,以便确保植入人体后的安全性,不是随便哪个材料都能做到这一点

耶鲁公开课 - 生物医学工程探索课程节选