Part B Listening Comprehension Directions: In this part of the test there will be some short talks and conversations. After each one, you will be asked some questions. The talks, conversations and questions will be spoken ONLY ONCE. Now listen carefully and choose the right answer to each question you have heard and write the letter of the answer you have chosen in the corresponding space in your ANSWER BOOKLET. 听力原文： Welcome to 'Consumer Today', the program aired daily this time, devoted to the consumers of the Washington Metropolitan area and their problems. Today's consumer complaint letter comes from Mrs. Arnie Smelt of Mac Clean, Virginia, who says: 'We've been living near the Dulles International Airport for five years and there has always been a noise problem caused by airplanes taking off and landing. But now that the Super Sonic Transport Jets are allowed to land at Dulles, the noise has become intolerable. We would like to sell our house and move to a quieter place, but we can't find a buyer who is willing to pay us anything near what the house is worth. What can we do?' In response to Mrs. Smelt's letter we have contacted the Environmental Protection Agency and they told us that there is nothing they can do about this problem. The Federal Aviation Administration gave us a similar answer. It seems that the United States Congress has final authority in this matter. Therefore we would like to urge each and every one of you listening to our program today to help by writing several letters: a letter to your district representative and a letter to each of your senators. Then, if you are brave enough, write a letter to the President telling him your opinion about the SST being allowed to use Dulles Airport. Questions: 1.Where is Dulles International Airport? 2.Which kind of pollution does Mrs. Smelt complain of? 3.Who was contacted by the 'Consumer Today' employees in response to Mrs. Smelt's complaint? 4.Who has final authority in this problem? (21)