Atmospheric Pollutants

Question 1

______ is/are our planet’s thermostat and the world’s chief greenhouse gas.

a)Water vapor

b)Atmospheric pollutants

c)Carbon dioxide

d)Ozone

Question 2 

Two students are discussing causes of desertification in semi-arid locales. Allen maintains that overcultivation depletes soil of vital nutrients. Audrey argues that overgrazing strips vegetation and leads to soil erosion and deforestation. Which student is correct?Question 12 options:

	a)Both Allen and Audrey are incorrect.
	b)Both Allen and Audrey are correct.
	c)Only Allen is correct.
	d)Only Audrey is correct.

Question 13 (2.5 points)

Plankton and phytoplankton represent the base of the oceanic food chain and produce about _______ percent of our planet’s atmospheric oxygen.Question 13 options:

	a)20
	b)30
	c)40
	d)50

Question 14 (2.5 points)

The ozone layer contains about _______ percent of atmospheric ozone.Question 14 options:

	a)60
	b)75
	c)90
	d)99

Question 15 (2.5 points)

Which statement best characterizes the temperate grassland biome?Question 15 options:

	a)The rainy season lasts for six to eight months.
	b)During the parched dry season, fires turn vegetation to ash.
	c)This biome features perennial grasses as well as flowering plants called forbs.
	d)This biome includes strands of trees separated by grasses.