14. Don’t waste her time __complaining_________(complain) about her salary.

giải thích:waste time +ving

15. That questions need __replying_________ (reply).

giải thích:need +ving

16. Viet is used to __crying______ (cry) when he faces his difficulties.

giải thích:to be used to ving

17. It’s time they stopped __working____ (work) here.

giải thích:stop+ving

18. Will she remember ___to collect____ (collect) his suit from the dry – cleaners or shall I do it?

giải thích:remember+v inf

19. Jim forgot __sending______ (send) this message last night.

giải thích:forget+ving

20. Hung stopped _to eat_____ (eat) meat yesterday.