An oprtator has to shoot a film. - An operator must shoot a film.
A veterinarian has to help animals with their health problems - A veterinarian must help animals with their health problems.
A doctor has to help people with their health problems. A doctor must to help people with their health problems. - Можно составить и так и такю Но have to , has to имеет значение необходимо , а must выражает большее должествование , т.е. надо, необходимо, если нужно выбрать только один вариант для предложения , то в первом, наверное has to - необходимо снять фильм, но может и не снимать , а во втором must т.к. ветеринар и доктор должны, обязаны животным, людям с проблемами здоровья . - Предлагаю такое решение
1. she's afraid of lifts, so she won't come in.
If she weren't , she would come in.
2. He's ill all the time because he has a very poor diet.
If he hadn't such poor diet, he wouldn't be ill all the time
3. I am so sad we missed Doug's art exhibition.
I wish we hadn't missed Doug's art exhibition.
4. If you don't leave now, we won't make it to her birthday party in time
We won't make it to her birthdayparty in time unless you leave now.
5. He didn't stop at the traffic light and he had an accident.
If he would had stopped at the traffic light, he wouldn't have had an accident.
