The _________ layer is always frozen in the tundra.
There are two types of grasslands: __________ and __________.
_______________ is another name for tropical grasslands.
The _____________ tundra is treeless, covers about 20 percent of the Earth, and has 24 hours of sunlight in the summer.
__________ species travel from cold to warm places during winter.
Some desert animals have two pairs of _________ to protect their eyes from the sand.
Grassland trees have thick ________ to protect them from brush fires.
Savanna
permafrost
barks
temperate/tropical
eyelashes
Migratory
Artic