If you have ever been rock climbing, then you will know that it is not a very easy sport. In fact you probably felt quite defeated when you first tried to do any serious climbing. Indoor and outdoor rock climbing are both extremely demanding and, like anything else, require practice, to get good at. What most people don’t know is that the sport of rock climbing is one of the most physically and mentally demanding sports there is. There are three basic types of rock climbing. Top roping is probably one of the most common types and is basically climbing with a partner. The second type, which is very similar to top roping, is called lead climbing. In both of these types of rock climbing the climber can sit off the wall and rest on the rope. The third type of rock climbing 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. Believe it or not, climbing is said to be about 75% legs and only 25% arms. 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 really is an amazing workout. Once you get into the sport, and learn how to position your body and rest your weight, then you can begin to deal with some difficult problems. 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. For anyone who wants to get into shape, rock climbing is a fun and effective way to exercise muscles. 41．What does the author think of rock climbing? A．It is an easy sport.          B．It is challenging. C．It is quite dangerous.       D．It is extremely difficult. 42．According to this passage, we know that __________. A．indoor rock climbing is much easier than outdoor rock climbing B．while rock climbing, people depend mainly on their arms C．ordinary people can practise rock climbing D．during climbing, the climber can always stop for a rest 43．It is much easier for a rock climber if he ___________ while climbing. A．takes a rope            B．has a partner C．has three points touching the wall   D．uses feet more often 44．___________ will make rock climb easier. A．Keeping the body closer to the wall   B．Resting more often on the arms C．Resting more often on the feet    D．Pushing forward without thinking of the problems 45．By rock climbing, one can _____________. A．get more weight and stronger muscles       B．get both physical and mental exercises C．have a terrible experience that will last long.   D．probably feel quite defeated