(E) 0.1
- Which of the following is an advantage of using green manure?
I. Leguminous green manures such as clover contain nitrogen-fixing
symbiotic bacteria in root nodules that fix atmospheric nitrogen in a
form that plants can use.
II. It increases the percentage of organic matter (biomass) in the soil,
thereby improving water retention, aeration, and other soil
characteristics.
III. The root systems of some varieties of green manure grow deep in the
soil and bring up nutrient resources that are unavailable to shallower-
rooted crops.
(A) I only
(B) II only
(C) III only
(D) I and III
(E) I, II, and III
- Which is probably the principal source of nitrates and phosphates?
(A) The water cycle
(B) Nitrogen fixation of lighting
(C) Bacterial decay
(D) Changes in environmental temperature
(E) Changes in light intensity
- Ocean water temperatures fluctuate less than air temperatures over land.
The primary reason for this phenomenon is (A) land absorbs more heat than
water
(B) winds distribute heat that builds up over the land
(C) there is more water on Earth than land
(D) the high heat capacity of water
(E) water both cools down and heats up faster than land
- Which of the following pollutants does NOT occur naturally in nature?
(A) Nitrous oxide
(B) Radon
