22.阅读下列短文，根据所读内容在文章后的横线上填入恰当的单词。注意：每个题号后只填1个单词。

　　If you have ever been rock climbing, you will know that it is not a very easy sport. Indoor and outdoor rock climbing are both extremely demanding and require practice to get good at.

　　There are three basic types of rock climbing. Top roping is the most common type and the climber needs to climb with a partner. The second type, which is very similar to top roping, is called lead climbing. In both of the types, the climber can sit off the wall and rest on the rope. The third type is called bouldering. Bouldering is a type of free climbing without any ropes. This is the most demanding of all climbing types. The climber must be able to complete the climbing without taking a rest on the rope.

　　To climb efficiently and successfully, a person needs to have a wonderful technique. One of the major rules of rock climbing is to always have three points touching the wall, whether it is both feet and one hand, or one foot and both hands, as it is much easier to have your weight rest on three points than on two. Another important idea to grasp is that your arms in most cases will do the climbing; they only hold you into the wall so that your legs are actually pushing you upward. Also, the closer you are to the wall, the easier it is to climb.

　　Rock climbing may sound a bit too extreme for the everyday person, but it is really an amazing workout. For anyone who wants to get into shape, rock climbing is a fun and effective way to exercise muscles. The great thing about rock climbing is that it is mentally challenging as well. You are constantly analyzing the way your body moves and how to do certain moves on the wall.

Title: Rock Climbing