"Stop, stop, " a passenger looked out of the window, and shouted at the young man, "you can't catch it ! "
"I must," the young fellow said, out of breath, "because I'm only driver of the bus.
out of breath上气不接下气
① The young man who was running behind the bus was tall.
② The bus was half full of passengers.
③ The bus was running very fast.
④ The passenger bad pity on the young man.
⑤ The young man was the driver.