1. 1. The composition of the air we breathe is about 78% nitrogen, 21% oxygen and 1% other gases. Which of these graphs best illustrates this information? a c b d

2. 2. In conservation plowing, why are dead weeds and stalks of the previous year’s crop left in the ground?
A. to keep the soil from becoming too fertile
B. to reduce the amount of seed needed for the next year’s crop
C. to retain moisture and hold the soil in place
D. to keep more organisms out of the soil

3. 3. Write the missing word or words in each sentence.
Natural resources provide people with ____, clothing, and shelter. (plants, food, or animals)
Plants and animals are both ______ resources. (renewable, nonrenewable, or nonliving)
Iron and oil are both ________ resources. (renewable, nonrenewable, or living)
Renewable resources are resources that can be ________. (used up, replaced, or eaten)

4. Tree________ Oil _________ Water _______ Coal ________
4. Write an “R” on the line if the natural resource is renewable. Write an “N” on the lie if the natural resource is nonrenewable.
Tree________
Oil _________
Water _______
Coal ________
Chicken ________

5. 5. Name three causes of wetland loss in Louisiana
5. Name three causes of wetland loss in Louisiana. Use complete sentences.