---Is this book Betty's? ----Yes , it's ________.
Our teacher warned us ______ play tricks _____ others. A. to; at B. not to; on C. not to; to
We must find a place _______. A. to live B. living C. to live in
I gave her some advice, but I don’t know ______ she’ll accept it. A. that B. whether C. Which
—I hear they took ____ active part in the school sports meeting. —_____ good boys they are! A.a; What a B. an; How C. an; What
—I’m in Class 4. Are you in Class 4, ____? —Yes, I am.