A．血 B．筋
C．肉 D．气
久卧损伤的是

系统在( )下出现负序电流。 点击查看答案

Around the world more and more people are taking part in dangerous sports and activities. Of course, there have always been people who have looked for adventure -- those who have climbed the highest mountains, explored(探询) unknown parts of the world or sailed in small boats across the greatest oceans. Now, however, there are people who look for an immediate pleasure from a dangerous activity which may only last a few minutes or even seconds. I would consider bungee(蹦极) jumping to be a good example of such an activity. You jump from a high place about 200 meters above the ground with an rope tied to your ankles. You fall at up to 150 kilometers an hour until the rope stops you from hitting the ground. It is said that 2 million people around the world have now tried bungee jumping. Other activities which most people would say are as dangerous as bungee jumping include jumping from tall buildings and diving into the sea from the top of high rocks. Why do people take part in such activities as these? Some psychologists(心理学家) suggest that it is because life in modem societies has become safe and boring. Not very long ago, people's lives were constantly under danger. They had to go out and hunt for food, and life was a continuous battle for survival(生存). Nowadays, according to many people, life offers little excitement. They live and work in relatively safe conditions; they buy food in shops; and there are doctors and hospitals to look after them if they become ill. The answer for some of these people is to look for danger in activities such as bungee jumping.What is special about bungee jumping?A．It is more dangerous,B．It is much easier to do.C．It is hard to find a proper place for it.D．It takes much shorter time to get pleasure. 点击查看答案