Question

【题目】 What color are icebergs (冰山)? White or blue? Surprisingly, there are green icebergs in Antarctica (南极). Their unusual color has confused scientists for years. But scientists have finally solved the mystery of the green icebergs.

Icebergs are large pieces of ice in the sea. Icebergs form after breaking away from glaciers (冰川).

Most icebergs are white. There are also many icebergs in Antarctica that are blue. Glacial ice has a lot of small air bubbles (气泡). The icebergs appear to be blue because the air bubbles reflect blue light.

However, there are no air bubbles in green icebergs, which means these icebergs are made out of sea ice rather than glacial ice.

But why does sea ice look green? Scientists at the University of Washington, US, recently found the reason--- iron oxide (氧化铁). It comes from rock dust found on the Antarctic mainland. After studying the green icebergs, scientists found that they have 500 times more iron than glacial ice. The iron comes from bedrock in the ocean. When glaciers grind (碾磨) against bedrock, a powder (粉末) that is rich in iron is created. The powder later mixes with ocean water, which then freezes as green sea ice, Stephen Warren from the university suggested.

This is an important finding because these green icebergs can deliver iron to far parts of the ocean. There, tiny sea plants use the iron as a nutrient (营养物). We thought green icebergs were interesting. But now they may actually be important.

【1】According to the story, icebergs can be ________.

A.white, blue and yellowB.green, blue and yellow

C.white, green and blueD.blue, red and green

【2】Some icebergs look green because ________.

A.there is iron oxide inside of themB.air bubbles inside reflect green light

C.some sea plants are frozen insideD.they are made out of bedrock

【3】The iron in green icebergs comes from ________.

A.glacial iceB.bedrock in the ocean

C.dead bodies of sea animalsD.industrial waste

【4】What can we infer (推断) from the story?

A.Green icebergs can only be found in Antarctica.

B.Glaciers don’t have any color.

C.Sea ice does not have air bubbles.

D.Antarctica animals feed on colorful icebergs.

【5】What’s the best title of the passage?

A.Iron OxideB.Mystery of the Green Icebergs

C.The Change of ColorsD.Differences between Glacial and Sea Ice

Answer 1

【答案】

【1】C

【2】A

【3】B

【4】C

【5】B

【解析】

本文是一篇说明文。主要讲述了美国华盛顿大学的科学家发现南极洲存在神秘的绿色冰山的原因—冰山里含有氧化铁。这些氧化铁来自南极大陆的基岩。

【1】细节理解题。根据文中“…there are green icebergs in Antarctica (南极).”，“Most icebergs are white.”，“There are also many icebergs in Antarctica that are blue.”可知冰山有绿色，白色，和蓝色。故选C。

【2】细节理解题。根据文中“Scientists at the University of Washington, US, recently found the reason—iron oxide (氧化铁).”可知有一些冰山看起来像绿色是因为里面含有氧化铁。故选A。

【3】细节理解题。根据文中“…The iron comes from bedrock in the ocean.”可知铁来自海洋中的基岩。故选B。

【4】推理判断题。根据文中“Surprisingly, there are green icebergs in Antarctica (南极).”可知在南极有一些绿色冰山，所以选项A错误。根据“... Glacial ice has a lot of small air bubbles (气泡). The icebergs appear to be blue because the air bubbles reflect blue light.”可知冰山是有颜色的，冰川冰有许多大量的小气泡，气泡反射蓝光。所以选项B错误。根据“…there are no air bubbles in green icebergs, which means these icebergs are made out of sea ice rather than glacial ice.”可知，绿色冰山中没有气泡，这意味着这些冰山是由海冰而不是冰川冰构成的。由此推理海冰里没有气泡。所以选项C正确。根据文中“…because these green icebergs can deliver iron to far parts of the ocean. There, tiny sea plants use the iron as a nutrient (营养物).”可知因为这些绿色的冰山可以把铁输送到海洋的很远的地方。在那里，微小的海洋植物利用铁作为营养物质。所以D选项错误。故选C。

【5】最佳标题题。根据文章的主旨句“…there are green icebergs in Antarctica (南极). Their unusual color has confused scientists for years. But scientists have finally solved the mystery of the green icebergs.”可知文章主要解释了为什么南极洲有些冰山是绿色的。故选B。