A：Betty, you look pale(苍白的)．Are you all right?

B：____A boy was riding his bike and listening to music．

A：That's very dangerous．What were you doing at that time?

B：____When the lights were turning to red，a car appeared．It wasn't going fast，but it didn't stop．

A：____

B：No．And the driver was talking oh his mobile phone．He didn't notice the boy．

A：Did the car hit the boy?

B：____ He just fell off his bike and hurt his knee．

A：That's too bad．

B：So when we're on the bike．we must be careful !

A：Yeah! ____

B：Yes, you're right．And we shouldn't listen to music.