题目内容
The author supports the theory of cell-mediated reactions primarily by ______.
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The author most probably believes that the antigen-antibody theory of immunological reaction______.
【C18】
Today's trumpet is one of the world's oldest instruments. It is the result of many centuries of development. Although it looks nothing like its ancestors, there are many similarities. All trumpets dire hollow tubes. They are all blown. And they all use the players lips to produce basic sound.
The trumpet developed as players and makers worked to improve its design, size, shape, material, and method of construction. They wanted to create an instrument that would produce a beautiful and attractive tone, enable the performer to play all the notes of the scale, extend the range higher and lower, make it possible to play more difficult music and, in general, be easier to play well. The remarkable way in which the modem trumpet achieves these goals is measure of the success of all those who struggled to perfect this glorious instrument.
The trumpet is actually the leading member of an entire family of .related instruments. There are trumpets of several different sizes, and in several different keys. There are comets, bugles, and a number of others that are all similar to the trumpet in the way they are made and played.
The trumpet family is much more than a group of related instruments that can stir one with their sound, or narrow tubes of metal capable of producing a variety of musical sounds. It is a link to many different periods of history and to people of many cultures. From the use of trumpets in ancient religious ceremonies to the part they play in modern rock bands, the trumpet family of instruments has much to tell about civilization and its development.
It can be inferred from the passage that ______ is needed to make the trumpet work.
Part A
Directions: Read the following three texts. Answer the questions on each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1.
In the past, American families tended to be quite large. Parents raising five or more children were common. Over the years, the size of the family has decreased. One reason for this is an increase in the cost of living. On the average, children attend schools for more years than they used to, making them financially dependent on their families longer. Moreover, children nowadays are better dressed and have more money to spend on entertainment. The parents usually take the responsibility for all the expenses. Meanwhile, families are less close than they used to be. More and more American mothers work away from home. The break up of the fatally occurs when the parents divorce. A lot of children in the U. S. live part of their young lives with only one parent. Broken families usually result in problems for children and parents alike. Children blame themselves when their parents separate. They grow up feeling unsettled as they are moved back and forth between parents. Usually one parent is responsible for raising the children. These single parents must care for the children's emotional and psychological needs while also supporting them financially. This is very demanding and leaves very little time for the parent's own personal interests. Single parents often marry other single parents. In this type of family, unrelated children are forced to develop brother or sister relationship. The situations of many American families today are not good. However, recent signs in licate that things are getting better. The divorce rate is declining. The rate of childbirth is rising. Perhaps Americans have learned how important families are.
In the past, American families tended to be______.
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