to-infinitive; -ing or base form?

I promised ____ one day.

• to come back

• coming back

• come back

It's no use _____ her.

• asking

• to ask

• ask

Carlos has suggested _____ a five-a-side football team.

• starting

• to start

• start

I've joined a gym ____ myself fitter.

• getting

• to get

• get

If you train too hard, you risk ____ yourself before the race.

• to injure

• injuring

• injure

What sport would you choose ____ if you had plenty of time and money?

• learn

• to learn

• learning

What sports do you avoid ____ and why?

• take part in

• to take part in

• taking part in

____ is essential if you want to perform well.

• Training

• Train

• To train

She was disqualified from the race for ____ an opponent.

• push

• pushing

• to push

This pool is fantastic! It's like ____ in the sea.

• to swim

• swim

• swimming