21. To make ______ way for _____ road built here two years ago，many old houses were pulled down.
A. a; the B. a; a C. /; a D. /; the
22. —Guess what! Yang Yang failed in the last round of the Super Girl Contest.
—How ______ it be? She is second to none in singing in my opinion.
A. shall B. might C. can D. must
23. Though your status is permanent, your identification card is ______ only for 20 years and has to be renewed regularly.
A．valid B．convenient
C．temporary D．secure
