问题 问答题

张三将全部的收入用于商品X和商品Y的消费。设他对这两种商品的消费已经满足。现在,设Px下降,Py和消费者收入保持不变。试分别在张三对X的需求价格弹性小于1、等于1和大于1时,讨论张三对Y的需求量会如何变化

答案

参考答案:

当张三对X的需求价格弹性eXd小于1时,表示张三对商品X的需求缺乏弹性。当商品X的价格下降,商品y的价格和消费者收入保持不变时,张三增加X的消费,但购买X所花的费用却减少,所以张三会增加对商品Y的消费,即张三对Y的需求量会增加。

(2)当张三对X的需求价格弹性eXd等于1时,表示张三对商品X的需求为单位弹性。当商品X的价格下降,张三增加X的消费,但购买X所花的费用不变,所以商品Y的价格和消费者收入保持不变时,张三对Y的需求量不变。

(3)当张三对X的需求价格弹性eXd大于1时,表示张三对商品X的需求富有弹性。当商品X的价格下降,商品Y的价格和消费者收入保持不变时,购买X所花的费用随着X的消费量的增加而增加,所以张三会增加对商品X的消费,而减少对Y的需求。

单项选择题 B1型题
阅读理解

The famous director of a big and expensive movie planned to film a beautiful sunset over the ocean, so that the audience could see his hero and heroine in front of it at the end of the film as they said goodbye to each other for ever. He sent camera team out one evening to film the sunset for him.

The next morning he said to the men, “Have you provided me with that sunset?”

“No, Sir,” the men answered.

The director was angry.  “Why not?”  he asked.

“Well,” one of the men answered, “we are on the east coast here, and the sun sets in the west. We can get you a sunrise over the sea, if necessary, but not a sunset.”

“But I want a sunset!” the director shouted. “Go to the airport, take the next flight to the west coast, and get one.”

But then a young secretary had an idea. “Why don’t you photograph a sunrise,” she suggested, “and then play it backwards, Then it’ll look like a sunset.” “That’s a very good idea!” the director said. Then he turned to the camera team and said, “Tomorrow morning I want you to get me a beautiful sunrise over the sea.”

The camera team went out early the next morning and filmed a bright sunrise over the beach in the middle of a beautiful bay. Then at nine o’clock they took it to the director. “Here it is, Sir,” they said, and give it to him. He was very pleased.

They all went into the studio. “All right,” the director explained, “now our hero and heroine are going to say goodbye. Run the film backwards so that we can see the sunset behind them.”

The “sunset” began, but after a quarter of a minute, the director suddenly put his face in his hands and shouted to the camera team to stop. The birds in the film were flying backwards away from the beach.

小题1:One evening, the director sent his camera team out ______.

A.to watch a beautiful sunset.

B.to find an actor and an actress.

C.to film a scene on the sea.

D.to meet the audience.小题2:Why did the director want to send his team to the west coast?

A.Because he changed his mind about getting a sunset

B.Because he was angry about his team

C.Because it was his secretary’s suggestion

D.Because he wanted to get a scene of sunset小题3:Which of the following is NOT true?

A.The team followed the secretary’s advice.

B.If you want to see a sunrise, the east coast is a place to go to.

C.The camera team wasn’t able to film the scene the first day.

D.The director ordered his team to stop filming the “sunset”小题4:The director wanted to film a sunset over the ocean because _____.  

A.it went well with the separation of the hero and heroine

B.when they arrived at the beach it was already in the evening

C.it was more moving than a sunrise

D.the ocean looked more than a sunrise小题5:After the “sunset” began, the director suddenly put his face in his hands _____.

A.because he was moved to tears

B.as he saw everything in the film moving backwards

C.as the sunrise did not look as beautiful as he had imagined

D.because he was disappointed with the performance of the hero and the heroine