to prep.对于；为了；(表示方向)到；向；(表示间接关系)给adv.（表示方向）去；（门）关上
双语例句
The key to the whole affair was his jealousy. 整个事情的症结是因为他忌妒。
Knowledge is a treasure, but practice is the key to it. [谚]知识是宝库，实践是钥匙。
Do you know the key to the problem? 你知道这道题的答案吗？
Seeing persons, however, do not need a metropolitan to find this key to beauty. 而能看见的人却不需要到大都会博物馆去找到这开启美的钥匙。
It would be with extreme reluctance that I should leave the Metropolitan Museum, which contains the key to beauty-- a beauty so neglected. 多么不情愿，我要离开大都会博物馆，那里有开启美的钥匙，这种美又被忽视了。
Here's your key to room218. 这是您218房间的钥匙。
Reading is the key to the treasure house of ideas. 读书是打开知识宝库的钥匙。
