5. You’re having a sore throat. You’d better___ to the doctor.
            A. to go          B. went                       C. go   D. going
6. My mother permitted me to go out at night. She said, “You ___ go out tonight.”
            A. may           B. have to      C. must           D. ought to     
7. He advised me to take an English course. I ___ it early.
            A. should have taken           B. should take           C. will have taken    D. may take
8. You ___ ring the bell; I have a key.
            A. mustn’t      B. needn’t      C. couldn’t     D. shouldn’t
9. It must ___ without delay.         
            A. be done     B. have been done    C. do   D. be doing
10. By the time a baby has reached his first birthday, he should ___ sit up or even stand up.
            A. to be able to         B. able to       C. to be able  D. be able to
11. Many birds will ___ more than 3,000 miles to reach their winter homes.
            A. flying        B. fly  C. be fly         D. flew
12. The pen won’t write; It ___ out of ink.
            A. must run   B. must be running   C. must have run      D. must have ran