4. The sentences below are from the radio program above. Complete the gaps with the correct verb form could or had to. Then listen again and check. a) In those times, the ancient Egyptians they used to build silos. make bricks that b) They also from rats and mice. think about how to keep their harvest safe c) The ancient Egyptians such as fruit, vegetables, and beans. plant different types of crops d) But ancient Egyptians year. plant crops throughout the whole e) The ancient Egyptians invent their own calendar.