D

The sun is setting on a summer night. At the entrance to a deep, dark cave, a few bats fly out. Then more and more of the small, furry creatures appear. Within a few minutes, a whole river of bats is pouring out of the cave, and they keep coming — millions and millions of them.

       Sound like a scary horror movie? Believe it or not, this scene takes place every night, all summer long, at Bracken Cave in Texas, where 20 million bats fly outside to feed on insects.

      Every March or April, Mexican free-tailed bats migrate up to 1,609 kilometers from their winter home places, like mines, tunnels, hollow trees, and under bridges in Mexico to this cave. Soon after they arrive, each mother gives birth to one baby bat. As many as 500 baby bats live crammed (挤) into one square foot of space, and those bodies create nice warm temperatures to keep them warm and comfortable. With bad sight, how can mother bats recognize their own babies? Their good sense of smell helps them the most.

      When the adult bats leave the cave at night to feed, they eat tons of insects in a single night, including many pests that eat farmers’ crops. And they get rid of mosquitoes, too.

      The cave, quiet in winter, is full of life all summer. The floor of the cave is covered with bugs. Gnats are flying around, and beetles are crawling up your leg when you walk in!

      When twenty million bats fly out of one cave opening, they make a column (柱) so thick that they show up on the radar at the nearby airport. So much for bats being scary!

B

  Iceland is a large island．In fact，it’s the world’s 18th largest island．Most of the population，however，lives in the southern part of the country，in or around the capital city of Reykjavik．By its very name，you’d expect Iceland to be mostly ice．Looking at Iceland on a map，you’ll notice it sits just outside the Arctic Circle．Despite this location and its name，Iceland actually has temperate climate because it’s warmed by the Gulf Stream．The Gulf Stream also helps keep Iceland’s coastal ports ice—free through the winter．

  There is plenty of ice on Iceland，though．The country consists of a large plateau(高原) that includes fields of sand，mountains and glaciers(冰川)．Over sixty percent of Iceland is tundra(苔原)．About fourteen percent of Iceland is lakes and glaciers．Only about twenty—three percent of the country has plants or vegetation of any kind．

  Iceland was settled in the late 800s and early 900s by Norsemen from the Scandinavian country of Nmway．Other settlers also came from Ireland and Scotland．From the thirteenth century up until 1918，Iceland was part of the Norwegian and later Danish monarchies．For most of that time，the small Icelandic population depended upon fishing and farming to make a living．For hundreds of years，Iceland was one of the poorest and least developed countries in the world．After World War Ⅱ，international aid and industrialization of the fishing industry turned Iceland into one of the wealthiest countries in the world．In 1914，Iceland became part of the European Economic Area，which allowed its economly to grow even more．

  Iceland is one of the youngest islands in the world．Surtsey rose out of the ocean during a series of volcanic eruptions between 1963 and 1968．Today，only scientists who study the growth of new life can visit the volcanic island of Surtsey．

C

     Bali is a tiny island that is part of Indonesia(印度尼西亚) today. It is a pretty island that has many mountains and a pleasant climate. For a long time, Bali was cut off from much of the world.

The people of Bali were happy and had a peaceful life. They were not allowed to fight. At one time there had been terrible wars on Bali. Then the people decided it was wrong to fight or have wars. They made rules to keep apart those people who wanted to fight.

Bali was divided into seven small kingdoms. The land around each kingdom was kept empty, and no one lived there. Since the kingdoms did not share the same borders(边界), the people could not fight about them.

On Bali, even children were not allowed to fight. If two children started a fight over a toy, someone separated them. When two boys argued, they would agree not to speak to each other. Sometimes they did not talk together for months; this gave the boys a chance to forget their anger.

Families who were angry with each other also promised not to speak. Their promise was written down, and the whole village knew about it. If they broke their promise, they had to offer gifts to their gods.

B

　　Iceland is a large island．In fact，it’s the world’s 18th largest island．Most of the population，however，lives in the southern part of the country，in or around the capital city of Reykjavik．By its very name，you’d expect Iceland to be mostly ice．Looking at Iceland on a map，you’ll notice it sits just outside the Arctic Circle．Despite this location and its name，Iceland actually has temperate climate because it’s warmed by the Gulf Stream．The Gulf Stream also helps keep Iceland’s coastal ports ice-free through the winter．

　　There is plenty of ice on Iceland，though．The country consists of a large plateau（高原） that includes fields of sand，mountains and glaciers（冰川）．Over sixty percent of Iceland is tundra（苔原）．About fourteen percent of Iceland is lakes and glaciers．Only about twentythree percent of the country has plants or vegetation of any kind．

　　Iceland was settled in the late 800s and early 900s by Norsemen from the Scandinavian country of Norway．Other settlers also came from Ireland and Scotland．From the thirteenth century up until 1918，Iceland was part of the Norwegian and later Danish monarchies．For most of that time，the small Icelandic population depended upon fishing and farming to make a living．For hundreds of years，Iceland was one of the poorest and least developed countries in the world．After World War Ⅱ，international aid and industrialization of the fishing industry turned Iceland into one of the wealthiest countries in the world．In 1914，Iceland became part of the European Economic Area，which allowed its economy to grow even more．

　　Iceland is one of the youngest islands in the world．Surtsey rose out of the ocean during a series of volcanic eruptions between 1963 and 1968．Today，only scientists who study the growth of new life can visit the volcanic island of Surtsey．