1
greenhouse
a building used to grow plants all year long
2
pollution
poisons, wastes, or other materials that cause harm
3
crowded
very full, or too full, of things or people
4
factories
buildings where products are made by machines
5
vats
a very large barrel, tub, or tank, used for holding liquid
6
scarce
in short supply
7
vertical
straight up and down; upright