考试网 >> 外语考试 >> 职称英语 >> 职称英语试题 >> 职称英语考试理工类(C级)试题及答案

发布时间：2006-06-23 21:00     点击：

　　One task for scientists today is to learn exactly which types of animal behavior predict quakes．It is not an easy job．First of all not every animal reacts to the danger of an earthquake．Jusf before a Califomia quake in l979，for example，an Arabian horse became very nervous and tried to break out of his stall．The horse next to him，however, remained perlectly calm．It is also difficult sometimes to tell the difierence between normal animal calmness and"earthquake nerves．"A zookeeper once told earthquake researchers that his cougar(美洲狮)had been acting strangely．It turned out that the cougar had a stomachache．

　　A second task for scientists is to find out exactly what kinds of warning the animals receive．They know that animals sense far more of the world than humans do．Many animals can see，hear，and smell things that people do not even notice．Some can detect tiny changes in air pressure．gravity,or the magnetism(磁力)of earth．This extra sense probably helps animals predict earthquakes．

　　A good example of this occurred with a group of dogs．They were closed in an area that was being shaken by a series of tiny earthquakes．Before each quake a low booming sound was heard．Each sound caused the dogs to bark(吠)wildly．The dogs began to bark during a silent period! A scientist who was recording the quakes looked at his machine．He realized that the dogs had reacted to a booming noise．They also sensed the tiny quake that followed it．The machine recorded both．though humans felt and heard nothing．

　　In this case there was a machine to check what the dogs were sensing．Many times，however, our machines record nothing out of the or dinary,even though animals know a quake is coming．The animals might be sensing something we do measure but do not recognize as a warning．Discovering what animals sense，and learning how they know danger signals，is a job for future scientists．

发表评论： 匿名发表 用户名: 查看评论

您将承担一切因您的行为、言论而直接或间接导致的民事或刑事法律责任 留言板管理人员有权保留或删除其管辖留言中的任意内容 本站提醒：不要进行人身攻击。谢谢配合。