Practice Exam 1 - Environmental Science - page 229

77. D
78. D
79. B
80. B
81. D
82. C
83. B
84. C
85. E
86. D
87. A
88. C
89. D
90. C
91. E
92. B
93. D
94. C
95. D
96. A
97. A
98. B
99. B
100. D
Answer Explanations
Section I: Multiple-Choice Questions
1. D Phosphorus is found mainly in sediment, with large amounts also found in oceans. Very small
amounts are found in the atmosphere in dust particles and sea spray.
2. C Vast quantities of carbon are stored in vegetation. The cutting down of forests and removal of vegeta-
tion releases this stored carbon into the atmosphere. Fossil fuels contain a large amount of carbon as
well, because they are made from the remains of organic matter. With the combustion of fossil fuels, the
trapped carbon is released.
3. E The carbon, sulfur, phosphorus, and nitrogen cycles all have been altered by humans. Carbon has
been altered through the burning of fossil fuels and removal of large amounts of the Earth's vegetation;