Question

---Must I go through the radiation(辐射)check when I come back from Japan at the airport these days?

---Yes, you _________．

1. A.
   can
2. B.
   may
3. C.
   might
4. D.
   must

Answer 1

D
情态动词。情态动词must意为“必要”时，引导的问句的肯定回答用must。