Some people associate migration mainly with birds. Birds do travel vast distances, but mammals also migrate. An example is the caribou, reindeer that graze on the grassy slopes of northern Canada. When the weather turns cold, they travel south until spring. Their tracks are so well-worn that they are clearly visible from the air. Another migrating mammal is the Alaska fur seal. These seals breed only in the Pribilot Islands in the Bering Sea. The young are born in June and by September are strong enough to go with their mothers on a journey of over 3,000 miles. Together they swim down the Pacific Coast of North America. The females and young travel as far as southern California. The males do not journey so far. They swim only to the Gulf of Alaska. In the spring, males and females all return to the islands, and there the cycle begins again. Whales are among the greatest migrators of all. The humpback and blue whales migrate thousands of miles each year from the polar seas to the tropics. Whales eat huge quantities of plankton. These are most abundant in cold polar waters. In winter, the whales move to warm waters to breed and give birth to their young.
81. From the passage we can learn that ______
A. people migrate like animals
B. only birds migrate
C. the female fur seals migrate only to the Gulf of Alaska
D. not all mammals migrate
82. The phrase "An example" underlined in Paragraph 1 refers to an example of a ______
A. migratory mammal
B. place where animals migrate
C. migrating bird
D. person who associates migration with birds
83. All the mammals are mentioned as migrating ones EXCEPT ______
A. caribou B. fin whale
C. reindeer D. Alaska fur seal
84. Where can you see from the air the migration of the mammals?
A. In the Pribilot Islands. B. In the Bering Sea.
C. In southern California. D. In northern Canada.
85. Which of the following is NOT true?
A. Whales breed in winter.
B. Young whales are given birth in cold waters.
C. Alaska fur seals give birth to the young only in one area.
D. Alaska fur seals are born in warm weather.
86. Together ______ of Alaska fur seals swim down the Pacific Coast of North America.
A. mothers and the young
B. fathers and the young
C. parents and the young
D. seals and whales
87. Which of the following is NOT described in the passage?
A. Whales migrate to breed and give birth to their young.
B. Whale-watching in Boston in summer is attracting.
C. Seals breed in the north before migration.
D. Reindeer feed on grass.
88. Whales live on ______
A. tiny plants and animals in the sea
B. the grassy slopes of northern Canada
C. their young in cold winter
D. the abundant seafood in tropic waters
89. How many kinds of migrating mammals are mentioned in the passage?
A. Four. B. Three.
C. Two. D. One.
90. What is the best title of the passage?
A. Three Types of Whales
B. Birds Migration
C. Mammals Also Migrate
D. Several Kinds of Migration
KEYS：
81.D[分析] 推断题型。
从文章前几句得知：一些人认为有迁徙习性的主要是鸟类……但哺乳动物也“迁徙”：其中一个例子是……。另一个迁徙的例子是……。由此推断出并不是所有的哺乳动物都迁徙;因此选项D是答案。本题也可用排除法做：选项A，B、C均是错误的，所以只有D是正确选项。
82.A[分析] 细节题型。
见上题分析，第二、三句提到哺乳动物也迁徙：其中—个例子是……。当然这个例子应是指迁徙的哺乳动物了。所以选项A是答案。
83.B[分析] 细节题型。
选项A和C在第三句中提及：选项D在第六句中提及：因此本题答案应为B。
84.D[分析] 细节题型。
见第三句、五句：An example is the caribou，reindeer that graze on the grassy slopes of northern Canada...Their tracks are so well-worn that they are clearly visible from the air.因此答案为D。
85.B[分析] 是非题型。
见文章最后一句：In winter，the whales move to warm waters to breed and give birth to their young.因此选项B为答案。
86.C[分析] 细节题型。
[注意本题容易选错]从文章Another migrating mammal is the Alaska fur seal These seals breed only in the Pribilot Islands in the Bering Sea. The young are born in June and by September are strong enough to go with their mothers on a journey of over 3,000 miles.Together they swim down the Pacific Coast of North America.The females and young travel as far as southern California.The males do not journey so far，中的划线部分可知，The females and young Alaska fur seal会从the Bering Sea(白令海——北太平洋的一部分)swim down the Pacific Coast of North America直到 southern California;而 The males也会从白令海南下(因为These seals breed only in the Pribilot Islands in the Bering Sea.)，只不过他们没有the females and young走的远罢了。因此选项C为答案。
