21.I tried to  ______ the hard work and the pain was worth it in the end .
    A.get along               B.get through      C.get over       D. get down
22.Students should take an active part in ________ after-class activities.
A.various          B.variety          C. vary          D. varieties
23.What ________ me was how the accident could have happened.
A.puzzle           B.puzzling        C. puzzled        D. puzzles
24.The island, joined ___ the mainland by a bridge , is easy to go.
A.on              B.in              C. at              D.to
25.A fire ________ in this hotel last night and three people were killed.
A.break out       B.break down    C.break into     D.break up
26.In ______ of our motherland, a large number of people lost their lives.
A.defend            B.defends         C.  defence        D. defending