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： Twins have always been a source of curiosity since they occur once in every eighty-six births. About one-third of all twins are identical, or single egg twins. Identical twins have the same genes and, hence, they have more similarities between them. Some identical twins are of difference to each other. For example, one may be left-handed, the other right-handed. As young children, some identical twins may look very much the same since they will be dressed up by their parents in the same way. But identical twins may think and dress alike even when they axe away from each other. In fact, the same thing happened to some identical twins when they were separated at birth and raised apart. They may pursue the same careers, have the same interests, or die at almost the same time. In contrast to identical twins, fraternal twins are not necessarily of the same sex. In some families there is a hereditary tendency to produce fraternal twins. Why do twins arouse our curiosity?