A.was trying / slipped / fell
B.tried / was slipping / falling
C.had been trying / slipped/ was falling
D.has tried / slips / falls

A.see / am walking
B.saw / was walking
C.was seeing / walked
D.have seen / were walking

A.wouldn’t
B.oughtn’t
C.needn’t
D.couldn’t

A.lost / have left
B.have lost / leave
C.have lost / left
D.were losing / had left

A.have gone / did not pay
B.will go / did not paid
C.go / would not pay
D.went / had not paid

A.does not rain
B.has not rained
C.had not rained
D.would not rain

A.was / have not been
B.had been / was not
C.would be / had not been
D.have been / will not be

A.are you doing / will go
B.have you done / would go
C.were you doing / went
D.will you do / are going

A.will arrive / take
B.arrives / will take
C.has arrived / am taking
D.had arrive / had taken

A.The team leader asked us to tidy up the final draft before submission.
B.The team leader reminded us to tidy up the final draft before submission.
C.The team leader ordered us to tidy up the final draft before submission.
D.The team leader simply wanted us to tidy up the final draft before submission.