If a preposition (in, at, to, for, by, after, about, etc) is followed by a verb, the verb ends in -ing. Preposition + ing.
 
For example:
 
Are you interested in presenting the plan?
I’m not very good at speaking in public.
I prefer driving to traveling by bus.
This equipment is only for cutting paper.
You can improve your English by reading more.
What did you do after finishing college?
How about meeting this morning?