Answer:
19. esta (la professora is a she, therefore the "estar" conjugation falls into the ella/el/usted category)
20. incorrect (soy is "ser" with "yo" conjugation, but "ser" is used to describe something that is permanent; you won't drink forever)
21. correct (it's the right conjugation)
22. same as number 20; it's incorrect for the some reason. the correct sentence is "yo estoy bebeindo"
Explanation:
