单选题 Ten years ago, when environmental lawyer Kassie Siegel went in search of an animal to save the world, the polar bear wasn't at all an obvious choice. Siegel and Brendan Cummings of the Center for Biological Diversity in Joshua Tree, Calif. , were looking for a species whose habitat was disappearing due to climate change, which could serve as a symbol of the dangers of global warming. Her first candidate met the scientific criteria—it lived in ice caves in Alaska's Glacier Bay, which were melting away—but unfortunately it was a spider. You can't sell a lot of T shirts with pictures of an animal most people would happily step on.
Next, Siegel turned to the Kittlitz's murrelet, a small Arctic seabird whose nesting sites in glaciers were disappearing. In 2001, she petitioned the Department of the Interior to add it to the Endangered Species list, but Interior Secretary Gale Norton turned her down. Elkhorn and staghorn coral, which are threatened by rising water temperatures in the Caribbean, did make it onto the list, but as iconic species they fell short insofar as many people don't realize they're alive in the first place. The polar bear, by contrast, is vehemently alive and carries the undeniable charisma of a top predator. And its dependence on ice was intuitively obvious; it lives on it most of the year. But it took until 2004 for researchers to demonstrate that shrinking sea ice was a serious threat to the bears' population. On Feb. 16, 2005—the day the Kyoto Protocol to curb greenhouse-gas emissions took effect, without the participation of the United States—Siegel petitioned to list polar bears as endangered. Three years later her efforts met with equivocal (不明确的) success, as Interior Secretary Dirk Kempthorne designated the bears as "threatened" (not endangered), a significant concession from an administration that has stood almost alone in the world in its reluctance to acknowledge the dangers of climate change. The Endangered Species Act (ESA) , whose odd lists of snails and bladderworts sometimes seemed stuck in the age of Darwin, had been thrust into the mainstream of 21st-century environmental politics. Break out the T shirts!

单选题 Siegel and Cummings hoped to choose an animal to ______.
A. call on people to take actions against global warming
B. make people aware of the danger of environmental damage
C. introduce to people a new concept of environmental protection
D. remind people of the importance of protecting endangered species

单选题 The problem with Elkhorn and staghorn corals lies in that ______.
A. they were not much-liked by many people
B. they were not well-known enough to be an icon
C. they were not considered animals by many people
D. they were not added to the list of Endangered Species

单选题 It can be learned that the polar bear ______.
A. was first considered by Siegel to be the iconic animal in 1998
B. was first proposed by Siegel to be the endangered species in 2004
C. was not qualified scientifically as the endangered species until 2005
D. was not officially under the government protection until 2008

单选题 Which of the following is chosen by Siegel as the symbolic animal?
A. The murrelet nesting in glaciers.
B. The polar bear in the North Pole.
C. The spider in Alaska's Glacier Bay.
D. Staghorn corals in the Caribbean.

单选题 Which of the following can best describe the author's attitude toward the U.S. position on global warming?
A. Indifferent. B. Understandable.
C. Appreciative. D. Critical.

单选题 The passage is focused on ______.
A. how the scientists tried to protect endangered species
B. how the symbolic endangered species has been chosen
C. the relation between global warming and endangered species
D. the problems in and the future of endangered species protection