Решение:
Выбираем подходящий модальный глагол, учитывая смысл предложения.
- Dogs can't fly. They can run fast.
- You should see a doctor if you have a high temperature.
- She must drive a car, she has a license.
- You must help your parents.
- We shouldn't cross the road on a red light.
Ответ: can't, can, should, must, must, shouldn't.