p175[音频]Lead-inTask1 Listen to an audio clip and tick the heading that best summarize its main idea.AAn introduction to the founder of SETIBAn introduction to the development of SETICAn introduction to the theory of SETIDAn introduction to the background of SETI
An introduction to the founder of SETI
B. An introduction to the development of SETI
C. An introduction to the theory of SETI
D. An introduction to the background of SETI