Snow is a form of frozen water.It contains many groups of tiny ice particles called snow crystals.These crystals grow from water particles in cold clouds.They usually grow around a piece of dust.All snow crystals have six sides，but they grow in different shapes.The shape depends mainly on the temperature and water levels in the air.

Snow crystals grow in one of two designs-plate­like and columnar.Plate­nar snow crystals look like sticks of ice.They form when the temperature is about five degrees below zero.

The shape of a snow crystal may change from one form to another as the crystal passes through levels of air with different temperatures.When melting snow crystals or raindrops fall through very cold air，they freeze to form small particles of ice，called sleet.

Groups of frozen water droplets are called snow pellets.Under some conditions，these particles may grow larger and form solid pieces of ice，or hail.

When snow crystals stick together，they produce snowflakes.Snowflakes come in different sizes.As many as one hundred crystals may join together to form a snowflake larger than two and one­half centimeters.Under some conditions，snowflakes can form that are five centimeters long.Usually，this requires near freezing temperatures，light winds and changing conditions in Earth’s atmosphere.

Snow contains much less water than rain.About fifteen centimeters of wet snow has as much water as two and one­half centimeters of rain.About seventy­six centimeters of dry snow equals the water in two and one­half centimeters of rain.

Snowfall helps to protect plants and some wild animals from cold，winter weather.Fresh snow is made largely of air trapped among the snow crystals.Because the air has trouble moving，the movement of heat is greatly reduced.

Snow also is known to influence the movement of sound waves.When there is fresh snow on the ground，the surface of the snow takes in，or absorbs，sound waves.However，snow can become hard and flat as it becomes older or if there have been strong winds.Then the snow’s surface will help to send back sound waves.Under these conditions，sounds may seem clearer and travel farther.

Generally，the color of snow and ice appears white.This is because the light we see from the sun is white.Most natural materials take in some sunlight.This gives them their color.However，when light travels from air to snow，some light is sent back，or reflected.Snow crystals have many surfaces to reflect sunlight.Yet the snow does take in a little sunlight.It is this light that gives snow its white appearance.

1．What plays a major role in determining the shape of snow crystals？(no more than 8 words)

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Do you ever imagine yourself on a quest(追寻)to unlock the secrets of civilization？If you do，Dan Brown’s new novel，The Lost Symbol，may be just the ticket.The novel is the third in Brown’s hugely popular adventure series.It follows Angels and Demons and The Da Vinci Code.

In Angels and Demons，Professor Robert Langdon races through Rome，saving the city from an explosion(爆炸)．In The Da Vinci Code，he solves a mysterious death in Paris and uncovers religious(宗教的)secrets that rock Christianity(基督教)．

In the new book Langdon is invited to Washington DC，the US capital，to give a lecture，following an invitation by a friend.He arrives to find the lecture has been cancelled(取消)．

There may be no audience but our hero does find a strange object，a severed(断开的)hand patterned with strange symbols pointing to a picture of George Washington，America’s first president.Langdon sees it as invitation to mysterious knowledge.

But the path to this knowledge is a difficult one.Langdon has to deal with soldiers who trail(跟踪)after him and the kidnapping(绑架)of a close friend.

Fans of Dan Brown’s writing will not be able to wait to get their hands on this latest of his books.It’s another exercise in the formula(模式)that proved so successful in The Da Vinci Code and Angels and Demons.

According to Monica Hesse，reporter with the Washington Post，Dan Brown’s greatest achievement is “the outsize(非常大的)impact his novels have had on the cities in which they’re set”．

Just ask Colin Glynne­Percy，director of the Rosslyn Chapel Trust，the Scottish church from The Da Vinci Code，where Langdon believed he could find the Holy Grail(圣杯)．

“Before the book came out，we had about 40,000 visitors a year，”Glynne­Percy says.“It went to 80,000.Then to 120,000.Then to 175,000.”The church has put in bathrooms and taken on staff to deal with the demand.

5．解析：细节推断题。辉格党发展成后来的自由党，自由党又为工党所取代，也就是说

辉格党不复存在了。

答案：A

4．解析：细节理解题。工党的建立的原因是工人阶级不愿受自由党和保守党的控制，且

这两大党都是代表富人利益的党派。

答案：D

3．解析：细节推断题。从原文可知，由于宗教上的原因，英国国教分化为清教徒和非清

教徒，这两支后来发展为辉格党和托利党。

答案：B

2．解析：细节推断题。选项C的意思是：两党制有利于建立一个有力的持久的政府。

答案：C

[解题导语] 在英国，现在控制议会的是保守党和工党。两党制既有利于资产阶级国家

议会内部相互制约又能使政府强大和稳定。英国两党制的形成和发展经历了几个阶段。

1．解析：指代考查题。文中介绍，资产阶级是为了强化国家机器，而让 “两党制” 形

成并存在的。

答案：A

4．Surges.

3．In the eye­wall.

2．No，they don’t.