Every day while Mike and Sally are playing outside, they can see a blind man walking on the street with a stick. It makes them surprised. “How can he walk on a busy street?” asks Mike. “It must be very ________,” says Sally.

Mike and Sally watch as the man walks. He walks slowly and ________. He walks to the traffic light and then stops. When the light turns ________, he starts walking again. He does not ________ anything as he walks. “It’s amazing. And it must be scary, too,” says Sally. “He knows where to go and when to stop as if he can see.”

One day, as the blind man was passing by, he heard the children talking. He stopped in front of them. “Hello, kids,” he said, “I hear you talking about how I walk.”

“Yes, we always ________ how you know where to go and when to stop on such a busy street. It is safer to stay indoors.”

The man smiled, “I train myself to listen very well. I can listen with my ears for every sound ________ I cannot see anything. I use my stick to help me, too. If my stick bumps (撞) into something, I know I need to stop and ________ it.”

The man continued, “Yes, it is safer to stay indoors, but I love to walk. I love the hot sun. I love the ________ of flowers. I love to hear the birds singing. Most of all, I love to get some exercise.”

Sally said, “Thank you. We have learned ________ today. We can see and walk. We should get some ________, too. You set a good example for us.”