Fill in the blank with correct answer

1. You ......out last night. I called several times but nobody answered the phone.
a. must be b. must have been
c. could have been d. should have been
2. Micheal’s score on the test is the highest in the class; .........last night.
a. he must have studied hard b. he should have studied hard
c. he must study hard d. he must had to study hard
3. Look! The yard is wet. It ......last night.
a. must rain b. couldn’t have rained
c. must have rained d. should have rained
4. We ....you more help, but we were too busy.
a. might have given b. might give
c. should give d. could give
5. You ....your pass at the entrance unless you are asked to do so.
a. mustn’t show b. needn’t show
c. haven’t to show d. B and C