题目内容：

    For centuries, men at sea have told stories about their experiences of seeing sea monsters like sea snakes and big whales．These stories are often considered as folk tales（民间传说）rather than real experiences．However, the large number of sightings and the use of modern technology are changing this attitude, making us wonder if those men were telling real experiences．

The following are some of the most well-known cases bout sea monsters living in the oceans．On August 6, 1848, in the Atlantic Ocean, seven men reported that they saw a creature about 60 feet long．The creature’s body was dark brown in colour except for its white throat area．The creature was swimming at a speed of 15 miles per hour with its head above the water．

In 1961, Mrs Stoudt and her sister were walking with their children along a strait in Washington D．C．when they saw something like a tree branch in the water．As the object moved closer to them, they saw a creature, which had a snake -like head and 3 humps（峰）．They said it looked like some sort of dinosaur．Then it moved even closer to them．Its frightening look made one of Mrs Stoudt’s children cry．

On December 12, 1964, French photographer Robert Serrec was having a holiday in Queensland, Australia．He was out off the coast in small boats with his family and friends．Suddenly, they noticed a creature, about 75-80 feet long．They described it as a tadpole-like（像蝌蚪的）creature with a snake-like head．They took pictures of the creature before it swam off．

1.What does the underlined word“cases”in Paragraph 2 most probably mean？

A.Boxes． B.Examples．

C.Explanations． D.Creatures．

2.Which of the following statements about the 1848 sea monster is not true？

A.It was about sixty feet long．

B.It kept its head above the water when it swam．

C.Its whole body was dark brown．

D.It was found in the Atlantic Ocean．

3.It can be inferred from the passage that       ．

A.the 1848 sea monster swam faster than the 1961 and the 1964 sea monsters

B.the three sea monsters mentioned in the passage each had a snake-like head

C.the 1964 sea monster was longer than the 1848 sea monster

D.Robert serre went to Australia in order to see a sea monster

4.The writer's purpose of writing the passage is       ．

A.to show people the danger of travelling by sea

B.to tell us that sea monster stories might be true

C.to explain why people are afraid of sea monsters

D.to tell people where they can find sea monsters