[解析]
AB(Text 7)
M:How was school,Helen?
W:Great,Dad!A woman called Ella came in to give a talk during our science class,and it was really interesting.Our teacher said she's quite famous.
M:Oh,really?
W:Yes.She works in a lab in the city,doing all sorts of experiments about how we can catch illnesses like colds.I spoke to her afterwards about how I want to be an animal doctor when I ' m older ,and she gave me lots of valuable advice .