21.The old temple _______ roof was damaged in storm is now under repair.
A. where B. which C. its D. whose
22.The two girls are so alike that strangers find ________ difficult to tell one from the other.
A.it B.them C.her D.that
23. –What’s the noise? It sounds as if it comes from upstairs.
--______ .It must be the window-cleaner working, next door.
A. I’m not sure B. I hope not C. I’d rather not D. I don’t think so