Here are the mistakes underlined and corrected:

33. You should to wash your **hands** before meals.
**Correction:** You should wash your hands before meals.

34. There are **some** milk to drink.
**Correction:** There is some milk to drink.

35. Walking is **gooder** than **traveling** by car.
**Correction:** Walking is better than traveling by car.

36. She **have** a round face.
**Correction:** She has a round face.