根据句意提示补全单词。
1. May I use a ________ if I get lost in the forest.
2. The boy is going ________with his cousin if it is sunny tomorrow.
3. Riding on the roadway is not ________.
4. When you ride on the roadway, it is important to ________ the traffic rules.
5. You should walk your bike across the ________ and in school.
，又截下原长的
，结果两根相差0.5米，这根铁丝原来的长度为（）米。