Gerund vs Infinitive

It is not worth... (waste) time on this useless conversation.

Mag coudn't help .... (smile) when her friend returned home and made a surprise for her.

There is no use ...(say) that this case is a piece of cake. It is really not!

It is so pleasant ... (have) a lie-in during the day.

I think your boss already imagines ...(be) on cloud nine after the awarding ceremony.

Every time I ask him, he chooses ... (keep) silent and go back to his room.

... (praise) your kid now is the best thing you can do for him/her.

My nephew entered this university ...(study) exact sciences

Lily thanked him for ... (be) so polite at the conference.

I wish he went on .... (learn) Japanese but he doesn't want to do that.

I don't think, she can afford ....(buy )such a fancy car. It's not hers.

Your neighbour came here just ... (poke) her nose into this extremely interesting situation.

That young lady appeared ...(be) really communicative and wise.