Green plant residues such as grass clippings or a green manure crop generally have a water content of about ________ by weight.
A) 75 B) 45 C) 25 D) 10 E) 95
Question 2
Which of the following is a greenhouse gas contributed to the atmosphere by soils?
A) carbon dioxide
B) nitrous oxides
C) methane
D) all of the above
E) none of the above