用所给词的适当形式填空。

1. She isn't at home. She must ________ (go) to school.

2. It takes us 20 minutes ________ (go) to school by bus.

3. That must be a lot more fun than ________ (ride) the bike.

4. Thank you for ________ (send) me the postcard.

5. I often help my son ________ (do) his homework.

以下哪种情况不能使用软膏（）。

A、有渗出的急性期湿疹

B、泛发性神经性皮炎

C、进行期银屑病

D、慢性湿疹