听力原文： High in dense bamboo forests in the misty, rainy mountains of southwestern China lives one of the world's rarest mammals: the giant panda, also called the panda. Only about 1,000 of these black-and-white relatives of bears survive in the wild.
Pandas eat almost nothing but bamboo shoots and leaves. Occasionally they eat other vegetation, fish, or small animals, but bamboo accounts for 99 percent of their diets. Pandas' teeth are very broad and flat. The shape of these teeth helps the animals crush the bamboo shoots, leaves, and stems they eat. There are many species of bamboo. Only a few of these grow at the high altitudes where pandas live today. A panda should have at least two bamboo species where it lives, or it will starve.
Giant pandas used to be able to move quite easily from one mountain top to another in search of food. Now the valleys are mostly inhabited by people. Pandas are shy; they don't venture into areas where people live. This restricts pandas to very limited areas.
Conservation organizations and Chinese government officials and scientists continue to work toward resolving the pandas' isolation problems. Maintaining "Bamboo Corridors" -- strips of undisturbed land through which pandas can comfortably travel from mountain to mountain-- is one of the many ideas that may help save the giant panda.
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A. 100.
B. 500.
C. 1,000.
D. 1,500.