Everybody's gone into the stadium and you can hear them cheering

27. I think the match ________. Everybody's gone into the stadium and you can hear them cheering.
a. was started b. will be started c. must started d. must have started
28. We found the exam extremely easy. We ________ so hard.
a. needn't study b. needn't be studying
c. needn't have studied d. needn't have been studied
29. There is plenty of money in our account so those cheques ________ to the bank today.
a. needn't be taken b. needn't be taking c. needn't take d. needn't taking
30. The picnic ________ because Peter has just had a traffic accident.
a. will cancel b. will be cancelling
c. will be cancelled d. will have cancelled