阅读理解。
In 1975, Junko Tabei became the first woman to reach the top of Mount Everest in the Himalaya
Mountains, the highest mountain in the world at 29,035 feet.
Junko was born in 1939 and grew up in a small town in Japan. During her childhood, she was thin and
weak. At age 10, Junko went on a school trip. The students climbed two mountains, and Junko loved it.
She could climb in her own time and ability.
After Junko graduated from university in 1962, she joined several climbing clubs. But they had mostly
men members. Some refused to climb with a woman. In 1965, Junko married a well-known Japanese climber.
Over the years, they climbed all the highest mountains of Japan.
Meanwhile Junko started a woman's climbing club. By 1972, she was chosen to lead a team of women to
climb Mount Everest. It took three years for the 15 women to train and raise money for their climb.
Finally in 1975, the team went to climb the mountain. They found nine guides to help them climb up the
mountain. Everything went well until the morning of May 4. Suddenly a huge amount of snow and ice fell on
them. One guide saved Junko. She rushed to help others. Everyone was alive but they had injuries, including
Junko. However, the team decided to continue their climb. About two weeks later, on May 16, Junko reached
the top of Mount Everest. Later she said, "I can't understand why men make all this fuss (过于关注) about
Everest-it's only a mountain."
1. When Junko was 10, she ______. [ ]
A. didn't like sports or games
B. often went on school trips
C. realized that she loved to climb
D. climbed mountains by herself
2. In 1972, Junko ______. [ ]
A. started a woman's climbing club
B. trained 15 women for their climb
C. raised enough money for a climb to Mount Everest
D. became a leader of a woman team to climb Mount Everest
3. During their climb to Mount Everest, Junko and her team ______. [ ]
A. got little help from the guides
B. went on climbing after they had injuries
C. had to stop climbing because of their injuries
D. spent nearly a month the whole way to the top
4. What does the author mainly want to tell us? [ ]
A. Mountain climbing is dangerous.
B. Women can do the same things as men.
C. Junko was the greatest climber in the world.
D. Junko had a very hard time before she succeeded.
，其中x为斜面对应的水平距离，由动能定理
可知，1的重力做功最多，1、2摩擦力做功相同，2、3重力做功相同，3的摩擦力做功最多，综上可知ABC均正确，选D。