Unit 7 Tall Buildings Part B,Lets review,序数词,Lets learn,A: Which floor do you live on,B: I live on the twelfth floor,A: Which floor does he live on,B: He lives on the fifteenth floor,A: Which floor do you live on,B: I live on the ninth floor,A: Which floor does she live on,B: She lives on the thirtieth floor,Grammar,Which引导的选择疑问句：表示哪一个，在一定范围内进行选择,如：Which color do you like? Which book do you like,Lets do,A: Which floor does he live on,B: He lives on the _ floor,twenty-third,A: Which floor does
