—I have a toothache.—You should .A.drink lots of water B.take a rest C.see a dentist

问题补充：

—I have a toothache.

—You should .

A.drink lots of water B.take a rest C.see a dentist

答案：

解析：A.drink lots of water喝大量的水 B.take a rest休息一下 C.see a dentist看牙医；句意：我牙痛。你应该去看牙医。故选C