In the last 250 years, the amount of carbon in the air has increased by percent. options:

10%

40%

80%

stayed the same

the "dirty dozen" chemicals banned in an international treaty are formally known as persistent organic pollutants, or pops. the united nations environment program provided this background on what they are and what they can do to humans and wildlife.

i hope this

a bird that nests only in a particular tree species.