1. According to the textbook, the world adds about __________ of CO2 to the atmosphere from fossil fuel combustion each year, whereas sustainable, stable amounts would be about __________.
A. 6 billion tons; 1 billion
B. 4 million tons; 1 billion
C. 8 billion tons; 3 billion
D. 4 billion tons; 6 billion
2. In 2006 the global oil prices reached slightly above __________ a barrel.
A. $108
B. $98
C. $88
D. $78
3. The advantages of __________ as an energy source are that it is abundant, versatile, and inexpensive compared with other energy sources.
A. coal
B. hydroelectric power
C. solar power
D. crude oil
4. During the 1990s, wind power grew at a rate of __________ while solar energy grew at a rate of __________.
A. 36%, 27%
B. 26%, 17%
C. 17%, 26%
D. 27%, 36%