Look at these sentences.
● Animals cannot survive for long without water.
● So desert animals have to find different ways of coping.
The first sentence says what cannot happen or be done; the second tells us what must, therefore, be done, what it is necessary to do.
Complete these sentences using cannot and have to/has to.
1. You __________ reach the island by land or air; you ___________ go by boat.
2. We __________ see bacteria with our eyes; we ___________ look at them through a microscope.
3. He __________ have a new bicycle now; he _________ wait till next year.
4. Old people often ___________ hear very well; they __________ use a hearing aid.
5. Road users __________ do what they wish; they ___________ follow the traffic rules.
6. She _________ accept this decision; she ____________ question it.
7. You __________ believe everything you hear; you ______________ use your own judgment.
