it is the key to 后跟不定式或v-ing形式均可，只是意思上不同。
the key to doing sth.
意为：做某事的关键，to是介词，后接名词或动名词；此时的 to doing sth是做定语修饰 key 。
the key to do sth.
意为：为了达成某目的的关键，后接不定式“to do sth"， to do sth作为目的状语存在。
扩展资料
例句：
1、The key to my recovery was meeting some really special friends who made me feel that Imattered because of who I was and not what I wore.
我所以能康复，关键是遇到了一些真正特别的朋友。他们让我感到，我之所以重要，不在于我穿什么衣服，而在于我这个人。
2、Modernization is the key to speed up our agricultural development.
现代化是加快农业发展的关键。
3、Nearly all of the young people interviewed believed that work was thekey to success.
几乎所有被采访的年轻人都认为工作是成功的关键。
