PART C Directions: You will hear three dialogues or monologues. Before listening to each one, you will have 5 seconds to read each of the questions which accompany it. While listening, answer each question by choosing A, B, C or D. After listening, you will have 10 seconds to check your answer to each question. You will hear each piece ONLY ONCE. 听力原文： The piano and violin are girls' instruments. Drums and trumpets are for boys. According to Psychologists Susan O' Neil and Michael Bottome, children have very clear ideas about which musical instruments they should play. They found that despite the best efforts of teachers, these ideas have changed very little over the past decade. They interviewed 153 children, aged between 9 and 11, from schools in northwest England. They asked them to identify four musical instruments and then say which they would like to play most and which they would least like to play. They also asked the children for their views on whether boys or girls should not play any of the four instruments. The piano and violin were both ranked more favorably by girls than by boys, while boys preferred the drums and trumpets. There was a broad agreement between boys and girls on which instruments each sex should play and the reasons varied. And while almost half of all boys said they avoided certain instruments because they were too difficult to play. Only 15 percent of girls gave that as a reason. Earlier studies indicated that very young school children aged between 5 and 7, showed no bias in choosing musical instruments. But their tastes become more clear between the ages of 8 and 10. One survey of 78 teachers suggested that after that age, both boys and girls begin to restrict themselves to the so-called male or female instruments. How many children did Susan and Michael interview?