Perhaps you ride a bicycle to school.       a bicycle can be great fun. Do you know   to ride a bicycle safely(安全地)?
Careful boys and girls learn to ride       bicycles well before they go out on the road. How can you tell whether(是否)you area good rider?
If you can ride a bicycle in a straight line, you can ride       .If you can't, you should practice riding       a safe place. To be safe on a bicycle, you need to use both hands and both      .Keep your feet on the pedals(脚蹬)and your hands on the handle bars(把手)all the time.
Do you have a       on your bicycle? If so, put your books and packages in it.Then you can keep      hands on the handle bars.
A bicycle is built for one person. It's not safe to carry     with you. So you must keep  when you ride a bicycle.