How the Hawaiian Islands Were Built
Volcanoes have been erupting on the earth for millions of years．More than five hundred still erupt today．These are called active volcanoes．Volcanoes are located in belts or chains．They are found where the earth’s crust is weak．The weak spots let the hot rock escape when the volcano erupts．
Many volcano belts are mountain ranges along the edges of continents．One belt runs along the western coast of South America up through the western part of the United States．Other volcanoes are found in ocean basins．
About threefifths of all active volcanoes in the world are in the Pacific Ocean．Many of these volcanoes erupt under the water．The Hawaiian Islands were built by volcanoes that began erupting under water and finally reached the surface of the ocean．
夏威夷群岛是怎样形成的
火山在地球上喷发已有几百万年的历史。有500多座火山至今还在喷发，这些火山叫做活火山。火山呈带状或链状分布，它们一般位于地壳脆弱的地段。火山喷发时，灼热的岩浆便从脆弱的地点流出。
许多火山带是一些大陆边缘的山脉。有一个火山带沿南美洲的西海岸向北，穿过美国的西部。另一些火山位于海洋盆地中。
世界上大约有3／5的活火山在太平洋，这些火山中有许多在水下喷发。夏威夷群岛便是由从水下喷发，最终达到洋面的火山而形成的。
The Antarctic，a Desert of Ice All Year Round
The antarctic is actually a desert．It is the only continent on the earth without a river or a lake．
The antarctic is all ice all year round．The warmest temperature ever recorded there is zero，at the South Pole．Explorers used to think that a place so cold would have a heavy snowfall．But less than ten inches of snow falls each year．That is less than half an inch of water．Ten times that much moisture falls in parts of the Sahara．
The little snow that falls in Antarctica never melts．It continues to pile up deeper and deeper year after year and century after century．When the snow gets to be about eighty feet deep it is turned to ice by the weight of the snow above it．
南极——终年冰封的不毛之地
南极地区实际上是一片不毛之地，它是地球上惟一没有河流也没有湖泊的大陆。
南极地区终年冰封。那儿历史上的最高气温纪录是零度，那还是在南极点。探险家们过去总认为，如此寒冷的地方可能会有纷飞的大雪，但是，那儿每年的降雪却不足10英寸厚，还没有半英寸水多。撒哈拉沙漠一些地区的降雨量还是那儿的10倍呢！
降于南极洲的微量的雪从不融化，年复一年，一个世纪又一个世纪地越积越厚。当积雪达80英尺的时候，受上层重压的雪就会凝结成冰。
A Temperature Change on the Moon
Astronomers can tell just how hot the surface of the moon gets．The side of the moon toward the sun gets two degrees hotter than boiling water．The night side reaches 243degrees below zero．
In an eclipse，the earth’s shadow falls on the moon．Then the moon’s temperature may drop 300degrees in a very short time．
A temperature change like this cannot happen on the earth．Why does it happen on the moon？Astronomers think that the surface of the moon is dust．On the earth，rocks store heat from the sun．When the sun goes down，the rocks stay warm．But the dust of the moon cannot store heat．So when the moon gets dark k，the heat escapes quickly．The moon gets very cold．
月球上的气温变化
天文学家们能准确说出月球表面的温度：月球阳面的温度比沸水高2度，其阴面温度低到零下243度。
在月食时，地球的阴影投射在月球上，这时月球的温度可以在瞬间下降300度。
像这样的温度骤变在地球上是不会发生的，但为什么会发生在月球上呢？天文学家们认为，月球的表面是尘埃，而地球上岩石能储存太阳的热量。当太阳下山时，岩石依旧保持温暖，但月球上的尘埃不能存热。所以当月球变得黑暗时，热量便迅速消失，月球便变得不胜寒了
How the Falls of Iguassu Was Discovered
In 1542，Alvar Cabeza de Vaca and his small band of soldiers guided their boats down a jungle river．It was the Iguassu，which now marks the boundary between Brazil and Argentina．Never had the explorers seen a river so beautiful．
At one point the men heard a strange rumble in the distance．It grew louder as they went on．Puzzled and afraid，they rounded a bend．Directly ahead of them the river vanished，plunging with a roar over the brink of a great chasm．
The men fought the swift current and managed to reach shore just in time to keep from being swept over the brink．Then they crept out on the wet rocks and looked into the churning caldron below．They had discovered the greatest waterfall that had ever been seen by white men－the falls of Iguassu．
伊瓜苏瀑布是怎样被发现的
1542年，阿尔瓦·卡维萨·迪·威卡和他的一小队士兵驾船来到一条丛林河的下游，这就是伊瓜苏河——现在巴西和阿根廷之间的边界河。这些探险家们从未看到过这样美丽的河流。
这时，士兵们听到远处传来一种奇怪的隆隆声，越往前走，响声越大。士兵们感到迷惑和恐惧，于是转弯绕行。就在他们的正前方，那条河却越过一个巨大断层的边缘，咆哮着急降而下，消失不见了。
士兵们与激流搏斗，及时到达了岸边，从而免遭被冲刷出断层边缘的厄运。然后他们爬到湿漉漉的岩石上，看着下面那口奔突翻滚的“大锅”。他们终于发现了白人从未见过的最大瀑布——伊瓜苏瀑布。
A Large Lake of Asphalt on the Island of Trinidad
At the village off La Brea，on the island of Trinidad，in the West Indies，is a large lake of asphalt called Pitch Lake．
The asphalt is hard and is dug out with a big scoop shovel or a pick，leaving a hole in the surface of the lake．Within a week or two the hole is filled with new asphalt that pushes up from below．The supply of asphalt seems to be endless．
An ancient legend explains how Pitch Lake came to be：Many centuries ago two Indian tribes fought a great battle．The victorious tribe built a village and held a victory celebration，They killed hundreds of beautiful hummingbirds，ate them，and used their feathers to decorate their clothing．The Great Spirit was so angered that the birds had been killed that he caused the entire village to sink into the earth．The crater where the village stood has been filled wish asphalt ever since．
特立尼达岛上的大沥青湖
在西印度群岛特立尼达岛上的拉布利亚村，有一个大沥青湖。
湖中的沥青很坚硬，用大勺铲或锄头挖出后，湖面上便留下了一个洞口。一两周内，洞又被地下涌出的沥青填满了。沥青的供应似乎是源源不断的。
一则古老的传说解释了沥青湖的来历：许多世纪以前，两个印第安人部落打了一次大仗，获胜的部落建立了一个村庄，并举行胜利庆典，他们杀死了数以百计的美丽的蜂鸟，吃了鸟肉，并且用鸟的羽毛装饰他们的衣裳；伟大的圣灵被这些蜂鸟惨遭杀害所震怒，便让全村沉入地下。从此，本是这村子原址的陷口便一直注满着沥青。
On the Beaches of Block Island
Doubloons worth a king’s ransom may lie buried on Block Island，nine miles off the Rhode Island coast．Many seventeenth century pirates visited there to plunder and to get supplies．
Only a hundred years ago，one story says，a ship anchored off shore one night and sailed out at dawn．Soon after，an island farmer found pieces of eight around a hole in his cornfield．Islanders are sure there is still treasure there．One man even kept“treasure rights”when he sold his property．
“Terrific place to bury treasure.”another islander said．He pointed at the vast expanse of beach and cliffs．“A body could come sneaking in here at night，bury his loot，and catfoot it out before anyone knew what was up．”
Probably not only pirates buried loot on the beaches of Block Island．Some early islanders were reputedly shipwreckers．No one knows how much booty they removed from ships lured by their lanterns to smash on the jagged rocks．
在布洛克岛的海滨