题目

函数y=ax+18与y=x+b互为反函数,则a与b的值分别为(    )A.a=1,b=3          B.a=-1,b=3              C.a=3,b=-6       D.a=-6,b=3 答案：提示：由y=x+b，得x=3y-3b，所以其反函数是f-1（x）=3x-3b.又因为函数y=ax+18与y=x+b互为反函数，所以3x-3b=ax+18，得a=3，-3b=18，即a=3，b=-6，故选C.答案：C 阅读理解． 　　Popular music in America is what every student likes．Students carry small radios with earphones and listen to music before class, after class, and at lunch．Students with cars buy large speakers and play the music loudly as they drive on the street． 　　Adult drivers listen to music on the car radio as they drive to work．They also listen to the news about sports, the weather, and the life of American people．Most of the radio programmes are music． 　　Pop or popular music singers make much money．They make a CD or tape which radio stations use in many places．Once the popular singer is heard all over the country, young people buy his or her tape．Some of the money from these tapes comes to the singer．Wherever the singer goes, all the young people want to meet him or her．Now the singer has become a national star． 　　There are other kinds of music that are important to Americans．One is called folk music．It tells stories about the common life of Americans．Another is called western or country music．This was started by cowboys who would sing at night to the cows they were watching．Today, any music about country life and the love between a country boy and his girl is called western or country music． 根据短文内容选择正确答案． (1) ________ kinds of music are mentioned(提到)in this passage． [　　] A． Two B． Three C． Four D． Five (2) When pop singers ________, they will become national stars． [　　] A． make much money B． make a CD or tape C． are loved by all the young people D． are wanted to sing on the radio (3) From the passage we know that country music is about the ________． [　　] A． common life of Americans B． country life and love stories C． life of cowboys D． school life in America (4) Which of the following is true according to this passage? [　　] A． Most students in America like popular music． B． Students with cars in America like to listen to music while driving． C． Adult drivers in America listen to music all the time while driving． D． Everyone in America wants to meet pop singers wherever they go． (5) What would be the best title(标题)for this passage? [　　] A． American Music B． Popular Music C． History of Music D． Western Music