Ответ:
Объяснение:
1. They are discussing the functions of brain now.
What are they discussing?
Are they discussing about functions of brain?
They aren't discussing the functions of brain now.
2. She has four brothers.
How many brothers she has?
Does she have four brothers?
She hasn't four brothers.
3. This time tomorrow morning I am attending the conference about drugs.
When am I attending the conference?
What conference am I attending?
This time tomorrow morning I am not attending the conference about drugs.
4. The doctor explained me the procedure yesterday.
When did the doctor explain you the procedure?
What procedure did the doctor explain?
The doctor didn't explain me the procedure yesterday.