1. It's the place where you sit before seeing the doctor. - Waiting room.
2. They are the tablets that you take when something hurts. - Painkillers.
3. It's a serious medical problem that causes a bad pain in your chest. - Heartache.
4. It's an illness you get if you eat bad food. - Stomachache.
5. It's a place where you can go when you're ill. - Hospital.
6. It's the help you give to someone who has been in an accident. - First aid.
Ответ: Сопоставление определений с составными существительными выполнено.