用情态动词 could, can, may, must, need 的正确形式填空。

1. —_______you answer this question in

   —Sorry, I_______.  _______I answer it in English?

   —No, you_______. You _______answer it in Chinese.

2. —_______ I ask a question?

    —Yes, you _______But you_______wait a minute.

3. —_______ I use your eraser, Bill?

   —Sorry, I don't have one. Ask Mary. She_______have one.

4. —_______you help me do the shopping?

   —OK, sure.

5. —_______you sweep the floor, please?

   —OK, but I_______finish my homework first..