a key figure / key points

关键人物/要点

house / car keys

房门的/车钥匙

Here is your key to Room 212.

这是你212房间的钥匙。

the key to the grammar exercises

语法练习的答案

Knowledge is a treasure, but practice is the key to it.

知识是一座宝库，而实践是打开宝库的钥匙。

My uncle tells me the key to his success is honesty.

我叔叔告诉我说他成功的关键是诚信。

Color is the key to making a room feel the way you want it to feel.

使房间有你想要的那种感觉，色彩是关键。

piano keys

钢琴键

Don't hit / strike the keys of the computer so hard.

不要那么用力地敲电脑的按键。