There are lots of extreme（极限） sports we can do today， and rock climbing is one of them． Many people enjoy rock climbing． And it is （1）b 　　 more and more popular．

You can do it indoors on （2）s 　　 walls or outdoors on real mountains． There are many（3）a 　　 of rock climbing﹣ ﹣it is fun and it also helps people forget their （4）w 　　．

The most important equipment（装备） to have （5）i 　　 good shoes． They need to be half a size （6）s 　　 than usual， so they aren't easy to fall off． The next thing you need is a harness（安全带）． This （7）a 　　you to move freely， but will hold you （8）u 　_____if you fall．It's important to know how to use your equipment．If you start to learn it，it's best to have lessons．People with （9）e 　　can help you a lot when you are learning to climb．

Rock climbing is very exciting for people of different ages． （10）C 　　，however，must be careful not to pollute the environment． Sometimes they leave rubbish on the mountains where they climb． They should take it with them and throw it away．