The air quality in the city, __________ is shown in the report, has improved in the past three  months.

   A. as  　　                   B. it    　                  C.  what               D. it  

 _______exercise early in the morning has become part of his retired life.

   A. Take                      B. Takes                    C.  Taken                     D. Taking

 In order to find the missing child, villagers _______ all they can over the past two years.

   A. did                      B. do                    C. have been doing    D. had done

 Every possible means _______ to prevent the pollution, but the sky is still gray.

   A. is used                  B. are used               

C. has been used          D. have been used

 An 8-year-old child shouldn’t do exercises _______ for 18-year-olds.

   A. intended                  B. to intend                

C. intending           D. having intended

 —How can I use this washing machine ?

   —Well , just _________ the instructions.

   A. look up                   B. refer to                

C. make up           D. agree to

 Only after they had discussed the matter for several hours _______ a decision.

   A. do they reach           B. did they reach       

C. they reached             D. they reach

 The doctor thought _______would be good for you to have a holiday.

   A. this                      B. that                    C. one                     D. it

 Though having lived abroad for years, many Chinese people still ______the traditional customs.

   A. perform                         B. observe                 C. possess                 D. support

 _______ party they held last night was completely _______failure.

   A. A; a                      B. The; the                C. The; a                  D. The; /