A、Math. B、Sport. C、Chemistry. D、Biology. C 对话中男士提到，虽然Allen也教数学，并且是一个优秀的橄榄球教练，但他的主科目是科学，其中尤以化学为主，虽然也教过生物。由此可见，化学是他的主科目。故答案为C)。

W: Today we are going to be talking to Robert Haycraft, (22) the chair of Excellence Teaching Committee which gives annual awards to the most outstanding teachers who’ve come to their attention each year. Robert, can you tell us first who is given The Great Teacher Award this year?
M: Well, it was quite competitive as there were quite a few exceptional candidates to choose from, but we decided in the end to give the award to Allen Liddell.
W: So what subject does Allen teach?
M: (23) Although he does teach math and is also an excellent rugby coach,his subject is science,particularly chemistry, though he has taught biology as well. He certainly makes impression on his students. He has an amazing talent to make experiments exciting.
W: So is his ability to stage a number of shows the main reason why you give Allen the award?
M: Well,good teaching is far more than showmanship. His skills go far beyond simply grabbing students’ attention with clever shows. (24) Allen has made his name in his own school, thanks to his passion for trying to understand the way each child learns and offer teaching to the needs and skills of each student.
W: What do his colleagues think of him?
M: Their head teacher nominated him for the prize. (25) He warmly praised his ability to get most reluctant students involved. Let me quote from the nomination: (25) Allen has always got this attitude and belief that he will never give up on anybody. He is always trying to motivate.
W: Is there anything else about Liddell’s own educational background that has profoundly affected his teaching style?
M: I think perhaps his own background has formed his faith in the need for personalized approaches to education.
22. What do we learn about Robert Haycraft?
23. What is Allen Liddell’s main subject?
24. What was the main reason why Liddell won the award?
25. What aspect of Liddell’s style has particularly struck the head teacher?