Which of the following holds the highest levels of oxygen?
A) Warm water near the surface of a marsh in Everglades National Park in May
B) Warm water in a mud puddle along a dirt road in Nebraska in June
C) Cold flowing water in a stream in Ontario in April
D) Water at the base of a waterfall that is formed from melting snow in mountains of Oregon in July
Question 2
Which of the following events may have contributed the most to the decline of fertility rates in the United States after 1963?
A) The Vietnam war
B) Improved methods of family planning
C) The Civil Rights movement
D) The lowering of the voting age to 18 years old in 1971