I am studying TOEFL iBT, I have this sample introduction to an independent writing section.

Although some people prefer to work alone, I believe it is much better to work in teams. The benefits for working in teams vastly exceed the convenience of working alone. In my opinion, there are two main advantages to working in teams over working alone.

My question is: why working became after to? I learned that after to we must use verb zero -or general- of the verb