20、He made a serious mistake，but then he corrected it         the situation got worse．

      A．until                   B．when                  C．before                    D．as

19、―It remains to be seen         the plan can be put into practice．

―It depends on your determination．

     A．whether               B．where                  C．how                      D．that  

18、He was having a meeting；otherwise he        over to help us．

      A．would have come                                     B．had come

      C．should come                                            D．came

17、He came back late，        which time all the guests had already left．

      A．during                B．at                        C．after                      D．by

16、John，you        television．Why not go out to play basketball?

      A．always watches                                       B．are always watching

      C．have always watched                                D．have always been watching

15、It         be a good movie―its reviews were very good．

      A．can                    B．should                 C．might                     D．need

14、I asked him to show me the record that         the meeting，but he refused．

      A．kept                   B．was kept              C．was kept of            D．kept of

13、The young man gradually        a knowledge of the subject．

      A．required             B．attained                C．achieved                D．acquired

12、John almost fell off the cliff, but managed to         until help came．

      A．keep on              B．catch on              C．count on                D．hang on

11、Intelligence doesn’t        mean success．You need to work hard as well．

      A．easily                 B．finally                  C．probably                D．necessarily