Ex 5. Choose the best answer 1. The plane ___ take off after the fog had lifted.A. mustB. canC. was able toD. may2. ___ you remember what you were doing at this time yesterday?A. CanB. MustC. MayD. Should3. I ___ understand this letter. Will you translate it for me?A. mustn’t B. may notC. can’t D. shouldn’t4. They have plenty of time, so they needn’t ___.A. be hurryB. to hurryC. hurryD. to be hurried5. You’re having a sore throat. You’d better___ to the doctor.A. to goB. wentC. goD. going6. My mother permitted me to go out at night. She said, “You ___ go out tonight.”A. mayB. have toC. mustD. ought to 8. You ___ ring the bell; I have a key.A. mustn’t B. needn’t C. couldn’t D. shouldn’t