在哪级维护中必须进行轮胎换位？

海德的态度转变理论是（）。

A．认知失调论

B．角色理论

C．社会交换论

D．平衡理论

Jim lives in a place _____Gum Tree.[ ]

A.calls  

B.calling    

C.called    

D.to call

音乐科学作为现实的大学专业，首先包括音乐的理论以及音乐历史的观点，它与音乐实践及音乐教育学的大学课程有所区别。例如，成为音乐会钢琴师的培训以及将其作为主修专业方向是音乐教师的教育途径。就此可以确定音乐科学一方面可划分为音乐史，也被称为历史音乐学；另一方面可划分为系统音乐学，也就是音乐民族学，也称音乐民俗学。但是很明显，音乐史构建了音乐科学的学习核心。它的主要任务是研究从古典时期到现代时期的音乐发展，包括对主要音乐家的生活和作品深入研究、对风格转变的学习以及对个别种类和历史时期进行的讨论。 从这段话中我们可以知道( )。

A．历史音乐学是音乐实践学习途径的一个下属领域

B．从音乐民族学角度来看，音乐民俗学是系统的音乐学研究的一个音乐实践的方面

C．音乐理论和历史的观点主要是在音乐学这个专业里得到研究

D．音乐理论和音乐实践的学习是和音乐学学习不同的

阅读理解

     America is a mobile society. Friendships between Americans can be close andreal, yet disappear

soon if situations change. Neither side feels hurt by this. Both may exchange Christmas greetings for a

year or two, perhaps a few letters for a while - then no more. If the same two people meet again by

chance, even years later, they pick up the friendship. This can be quite difficult for us Chinese to

understand, because friendships between us flower more slowly but then may become lifelong feelings,

extending (延伸) sometimes deeply into both families. 

     Americans are ready to receive us foreigners at their homes, share their holidays, and their home life.

They will enjoy welcoming us and be pleased if we accept their hospitality (好客) easily.

     Another difficult point for us Chinese to understand Americans is that although they include us warmly

in their personal everyday lives, they don't show their politeness  to us if it requires a great deal of time.

This is usually the opposite of the practice in our country where we may be generous with our time.

Sometimes, we, as hosts, will appear at airports even in the middle of the night to meet a friend. We may

take days off to act as guides to our foreign friends. The Americans, however, express their welcome

usually at homes, but truly can not manage the time to do a great deal with a visitor outside their daily

activities. They will probably expect us to get ourselves from the airport to our own hotel by bus. And

they expect that we will phone them from there. Once we arrive at their homes, the welcome will be full,

warm and real. We will find ourselves treated hospitably.

     For the Americans, it is often considered more friendly to invite a friend to their homes than to go to

restaurants, except for purely business matters. So accept their hospitality at home!

1. Which of the following statements is TRUE according to the passage?

A. Friendships between Americans usually extend deeply into their families.

B. Americans will continue their friendships again even after a long break.

C. Americans always show their warmth even if they are very busy.

D. Friendships between Americans usually last for all their lives.

2. From the last two paragraphs we can learn that when we arrive in America to visit an American

    friend, we will probably be ______.

A. treated hospitably at his home      

B. offered a ride to his home

C. warmly welcomed at the airport

D. treated to dinner in a restaurant

3. The underlined words "generous with our time" in Paragraph 3 probably mean ______.

A. strict with time                  

B. serious with time

C. willing to spend time            

D. careful with time

4. A suitable title for this passage would probably be "______".

A. Friendships between Chinese    

B. Friendships between Americans

C. Americans' hospitality        

D. Americans' and Chinese's opinions of friendships

一次性办理长调车进路时，进路中所有的按钮表示灯都闪白灯。始端是由（）接点接入闪光电源，中间信号点是由（）接点接入闪光电源，终端是由（）接点接入闪光电源。