Respuesta :
Answer:
B and C
Explanation:
A) wrong because valley has nothing to do with the envoiorment,
B) correct beacsue the guly coast has heavy pollution problems in their water which can affect the air and that air travels over mexico city
C) correct, a big population can equal alot of litter!
D) wrong theyre has been some left over from that but thats not really quite dealing with the question
C and D
C because 20 million people produce a lot of pollutants.
D because rainforests reduce air pollution.
C because 20 million people produce a lot of pollutants.
D because rainforests reduce air pollution.