Ответ:

2. + = We have done our homework

    ? = Have you done your homework?

3.   ? = Did you bring any change?

     - = I haven't brought some change to buy a drink

4.  + = Yes, he have won a medal for swimming

    - = No, he haven't won a medal for swimming

Объяснение: надеюсь помог

2. Has Violet ever been skiing?

Violet has never been skiing.

3. Have you brought any change to buy a drink?

I haven't brought any change to buy a drink.

4. Yes, he have won a medal for swimming

No, he haven't won a medal for swimming