Answer:
los alumnos escuchan a el profesor
A, because como estas is familiar, como esta usted is formal (someone older than you)
Answer:
A: I really like the kind of the tablet
B: I really like the kind of cell phone
C: I really like ecology class
D: I really like the class of the charger
(Definitely not D, I'd say C)
Listen to the radio in the evenings.
