Long ago people send messages in different ways. A man put his ear to the ground. He 1 the horses. They were coming this way. He ran to 2 his people. He was a 3 .That was one way to send messages. People in 4 different countries also send messages. One man made a cloud of smoke. In the next village people saw the smoke and went on doing that, too. The message went from village to village by 5 . 6 some soldiers(士兵)kept many pigeons(鸽子),these pigeons 7 flew back. If a soldier was sent far away from his own 8 , he might take a pigeon along. He could tie a message to the bird's leg. It would fly back 9 the soldier's message. These were slow ways to send messages. Can you think of any 10 ways?