We know that many animals do not stay in one place. Birds, fish and other animal
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We know that many animals do not stay in one place. Birds, fish and other animals move from one place to another at a certain time. They move for different reasons：most of them move to find food more easily, but others move to get away from places that are too crowded.
When cold weather comes, many birds move to warmer places to find food. Some fishes give birth in warm water and move to cold water to feed. The most famous migration（迁移）is probably the migration of one kind of fish, which is called “salmon”. This fish is born in fresh water but it travels many miles to salt water. There it spends its life. When it is cold, it returns to its birthplace in fresh water. Then it gives birth and dies there. In northern Europe, there is a kind of mouse. They leave their mountain homes when they become too crowded. They move down to the low land. Sometimes they move all the way to the seaside, and many of them are killed when they fall into the sea.
Recently, scientists have studied the migration of a kind of lobster（龙虾）. Every year, when the season of bad weather arrives, the lobsters get into a long line and start to walk across the floor of the ocean. Nobody knows why they do this, and nobody knows where they go.
So sometimes we know why humans and animals move from one place to another, but at other times we don't. Maybe living things just like to travel.
(1) Most animals move from one place to another at a certain time to _____.
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A．give birth
B．enjoy warmer weather
C．find food more easily
D．find beautiful places
(2) The fish called “salmon” spends a long life in ______.
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A．salt water
B．rivers
C．fresh water
D．its birthplace
(3) The mice in northern Europe move when ______.
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A．they give birth
B．the weather is bad
C．the place gets too crowded
D．they haven't enough food
(4) What is the main idea of the passage?
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A．Animals move in order to find food more easily.
B．The migration of the fish called “salmon” is the most famous migration.
C．Living things move from one place to another because they like to travel.
D．Sometimes we know why and how living things move from one place to another, but sometimes we don't.
试题答案
答案：C;A;C;D
解析：(1)乍一看，四个选项好像都在文中叙述过，但仔细一看题干的“most animals”这一关键词语，便可排除A，B，D项．见第一自然段的“They move for different reasons：most of them move to find food more easily…” (2)有关“salmon”的情况在第二自然段中间作了叙述．这种鱼出生在淡水后到咸水地区居住．在那里度过的是一生有大部分时光，到老了以后又回到它出生之时的淡水之中．应仔细分析题干中的“spends a long life”和短文中的关键句“There iv spends its life.” (3)从“They leave their mountain homes when they become crowded.”一句可知． (4)文中第二自然段叙述了“salmon”和北欧的一种老鼠的迁移方向和原因；第三自然段叙述了龙虾的游动情况，但原因不知道．最后一段开头第一句也正是对本文主题的综述． |