--Where’s the library?
--It’s____ the first floor.
A. inB. on C. at
Let ____ help you.
A. my B. I C. me
There are 4 _______ in our classroom.
A. wall B. the wall C. walls
Where’s the ______ office?
A. teacher B. teacher’s C. teachers’
-- _____time is it？
-- It’s 2 o’clock.
A. Where B. What’s C. What