By the time I _____back they _____up ten meters.

题目

By the time I _____back they _____up ten meters.
A.came...have climbed
B.came...had climbed
C.come...have climbed
D.had come...climbed
Jack ____over five lessons by seven o'clock.Then he ____a test.
A.went...took
B.went...had taken
C.had gone...took
D.had gone...taken
Many volunteers will _____Shanghai Special Olympics World Games in 2007.
A.attend
B.join
C.go to
D.take part in

答案

B
C
D
头两个都是过去的过去发生的事情,用过去完成时.
最后一个attend较为正式,一般为会议之类的,指“出席”,join参加,指参加比赛等等,go to只是去,并不参与这一活动,take part in指参与,并非参加比赛,由"volunteer"一词可知他们只是作为志愿者参与,不是参加比赛,故选D.