【BythetimeI_____backthey_____uptenmeters.A.came...haveclimbedB.came...hadclimbedC.come...haveclimbedD.hadcome...climbedJack____overfivelessonsbyseveno'clock.Thenhe____atest.A.went...tookB.went...hadtakenC.hadgone...tookD.had】

　　BythetimeI_____backthey_____uptenmeters.

　　A.came...haveclimbed

　　B.came...hadclimbed

　　C.come...haveclimbed

　　D.hadcome...climbed

　　Jack____overfivelessonsbyseveno'clock.Thenhe____atest.

　　A.went...took

　　B.went...hadtaken

　　C.hadgone...took

　　D.hadgone...taken

　　Manyvolunteerswill_____ShanghaiSpecialOlympicsWorldGamesin2007.

　　A.attend

　　B.join

　　C.goto

　　D.takepartin