Most shells of marine organisms are composed of:
a. gypsum
b. silica
c. calcite
d. either b or c
d
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Which one of the following statements about polar bears is not true?
a. In 2008, the U.S. Fish and Wildlife Service placed the Alaskan polar bear on its list of threatened species. b. Alaskan state government officials are trying to have the polar bear delisted. c. Polar bear populations are a significant threat to wolf populations in Alaska d. Oil and coal industry leaders want the polar bear delisted in Alaska e. Less than 60% of the world population of polar bears lives in Alaska
Which of the following features is created at a divergent plate boundary?
A) mountain building at the margin of the continent B) oceanic trench C) subduction zone D) continental crust E) rift valleys
The following country has a very large population, medium developing HMI ranking, and exhibits considerable inequality in HDI within its country
A) Madagascar B) Mexico C) India D) United States E) Russia
Approximately what percentage of incoming solar radiation is absorbed by the oceans and continents?
A) carbon dioxide B) methane C) nitrous oxide D) ozone E) water vapor