Ⅰ、1、buildings
2、gate
3、playground
4、library
5、near
6、science
7、behind
8、office
9、dining
10、same
Ⅱ、11、where
12、aren't
13、in front of
14、there isn't
15、What is
Ⅲ、16-20：C C B B B
21-25：C A A C B
Ⅳ、26、behind the door
27、between the library and，lab
28、in the middle of
29、with a garden
30、writing