A) clean air
B) dirty air
C) dirty water

A) watching TV all night
B) reading a book before bed
C) playing video games.

A) to make them wet
B) to remove dirty and germs
C) to remove dirty and germs

A) trees
B) flowers
C) cars

A) 9 – 10 hours.
B) 5 – 6 hours
C) 7 – 8 hours

A) before bed
B) after every meal
C) both a and b

A) burning more garbage.
B) planting more trees
C) using more cars

A) playing video games.
B) brushing your teeth and reading a book
C) eating lots of candy

A) to be loud
B) to keep warm
C) to prevent spreading germs

A) listening to music.
B) factory smoke
C) cooking at home