头脑清醒

Mountaineering is dangerous, so you need to keep your wits about you.

登山是危险的运动，你必须时刻清醒。

A whiff of fresh air cleared his head.

他吸了一点新鲜空气后清醒了。

If a marriage is to work, both partners must go into it with their eyes open.

如果想要满，那么在步入堂的时候两个人都清醒，知道意味着什么。