假如你是班长，要向全班同学作一个口头通知。请根据下列内容提示用英文拟一个口头通知。

Don’t Ride Too Fast Dick: What’s the matter，Bill?Why are you sitting on the ground? Bill: I fell off my bike and hurt my leg. Dick: I’m sorry to hear it .Is there anything I can do for you? Bill; Would you please phone my father and tell him to come at once? Dick: Is he in his office or at home? Bill: In his office and his telephone number is 553246. Dick: 553246，I’ve got it down .Now I’ll run to the nearest publicphone.Wait for me here. Bill: OK. You can ride my bike. It’ll save time. Dick: That’s a good idea.It’ll be back soon. Bill: please don’t ride too fast. Dick: Don’t worry .I won’t.