No single adjective is adequate to describe the size of the blue whale，and few people realize how it compares with other mammals.By any standard，it is the largest creature known to man.To be specific， one of its fins，called a fluke，would fill the cargo space of the acerage dump truck.Although its skull is the size and weight of a car，its brain is only the size of a carburetor.Its heart is so large that five strong men would be needed to lift it，while its skin could be used as a tarpaulin to cover half a football field.Every person in Boston could be supplied with a whale burger，and a pretty good one，too，from the meat of one blue whale.Combine the weights of 100 horses，100 dairy cows，and 5 Indian elephants，and you would arrive at the weight of one female blue whale.Fortunately，for the whale，its watery environment has protected it from the extinction suffered by the dinosaur millions of years ago.

1.Which sentence best expresses the main idea？

A.Although the blue whale is enormous，its brain is very small.

B.The meat of the blue whale is one of the tastiest meats known to man.

C.Female blue whales are larger than males.

D.The blue whale is one of nature’s largest and most fascinating wonders.

2.The author develops his main idea by____.

A.giving the reasons for its enomous growth

B.using descriptive adjectives

C.comparing its size to known objects

D.defining its watery environment

3.The paragraph could be entitled____.

A.A Close Look at the Blue Whale

B.Useful Products from the Blue Whale

C.Mammals of the Deep

D.The Survival of the Blue Whale