题目内容：

People often think of the North Pole and the South Pole as similar frozen wastelands. They are both places with very cold temperatures and few people live there. However, the North and South Poles are not much alike as people may imagine.

The North Pole has no land, only thick ice. Temperatures seldom go above 32 F, at which water turns into ice. Most of the time, it stays below zero. In winter temperatures are usually as low as -30 F.

Although conditions were very poor, people tried for many centuries to reach the North Pole. About 100 years ago, two men, Robert Peary and Mathew Henson, were able to get to this environment full of troubles and difficulties. They reached the North Pole on March 8th, 1909. It was really a hard trip for them.

There are few things more dangerous than crossing the Arctic(北极圈)on foot. People who stayed there may face many problems: very cold temperatures, sudden storms, and even hunger. Most of the area is uninhabited(无人居住的). Few people can live in such a difficult place.

People might think that with such low temperatures for most of the year, the ice would be thick and hard. However, this is not true in the Arctic. The movement of the ocean water under the ice may often cause many different changes on the surface. Sometimes the ice breaks into two opening lanes of water(水道)called "leads". Anyone who falls into a lead can be frozen to death in a few minutes.

1.This passage is probably from       .

A. a book review    B. a science book

C. a school report    D. a computer magazine

2.According to the passage what happened about 100 years ago?

A. The North Pole changed into thick ice because of the temperatures.

B. Temperatures in the North Pole went above 32 F.

C. The environment in the North Pole suddenly became worse.

D. Two men succeeded in getting to the North Pole.

3.What does this passage mainly talk about?

A. The thick ice in the North Pole.

B. A difficult trip to the North Pole.

C. The real situation in the North Pole.

D. The differences between the North Pole and the South Pole.