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

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

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

A) flowers
B) cars
C) trees

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

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

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

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

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

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