If I______, I would have said hello

13.If I______, I would have said hello.
    A. had seen    B. saw    C. see    D. would see
16.    If she______ him, she would be very happy.
    A. met    B. had met    C. meets    D. has meet
22. To______ is to become, or making something become, twice as much as or as many as usual.
    A. double        B. increase         C. decrease         D. rise