题目内容
Why don’t birds get lost on their long flights from one place to another Scientists have puzzled over this question for many years. Now they’re beginning to fill in the blanks. Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly by night Tests with artificial stars have proved that certain night - flying birds are able to follow the stars in their long- distance flights. A dove (鸽子)had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The bird’s cage was placed under an artificial star-filled sky. (76) The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the artificial stars caused a change in the direction of his flight. (77) But the stars are apparently their principal means of navigation(航行)only. When the stars are hidden by clouds, they seemingly find their way by such landmarks as mountain ranges, coast lines, and river courses. But when it’s too dark to see these, the doves circle helplessly, unable to find their way. The experiment with the dove implied that ______.
查看答案
搜索结果不匹配？点我反馈
更多问题
A group of people who share the same interests and way of life is called a society. Sociology is the science that examines human society. The term sociology is derived from the Latin word socius, which means "companion, union of people". (80) Sociologists are interested in how a society began and how it grew. They also study the levels within a society. For example, the child is part of the family, the family is part of the neighborhood, and the neighborhood is part of the community. There are many different groups, and sociologists are interested in the effect that these groups have on people. A Frenchman named Auguste Comte made sociology a separate science in the l’830s. He suggested that a new science was necessary to study a society of people. A famous book, Principles of Sociology, was published by an Englishman, Herbert Spencer, in 1882. This book had an unprecedented(史无前例的) effect on the science of sociology. In this book, Spencer theorized that a society’s customs evolved, or grew, from very simple to more complicated and advanced. This theory shows the influence that Charles Darwin (who believed that man had evoked from very simple forms to the present human) had on Spencer. The book which had a great influence on sociology was written ______.
某系统集成商依据《电子信息系统机房设计规范GB 50174-2008))为F省某所重点大学设计网络中心机房。在以下网络机房设计要点(方案)中，不符合规范的是___10___。该网络机房为隶属于校办公室的机要科专门设置一间电磁屏蔽室。在以下该电磁屏蔽室的设计要点(方案)中，不符合规范要求的是__11____。对于该大学连体式教研办公综合大楼，在___12___情况下，能够依据《大楼通信布线系统》(YD/T926)进行结构化综合布线。 10（）
A group of people who share the same interests and way of life is called a society. Sociology is the science that examines human society. The term sociology is derived from the Latin word socius, which means "companion, union of people". (80) Sociologists are interested in how a society began and how it grew. They also study the levels within a society. For example, the child is part of the family, the family is part of the neighborhood, and the neighborhood is part of the community. There are many different groups, and sociologists are interested in the effect that these groups have on people. A Frenchman named Auguste Comte made sociology a separate science in the l’830s. He suggested that a new science was necessary to study a society of people. A famous book, Principles of Sociology, was published by an Englishman, Herbert Spencer, in 1882. This book had an unprecedented(史无前例的) effect on the science of sociology. In this book, Spencer theorized that a society’s customs evolved, or grew, from very simple to more complicated and advanced. This theory shows the influence that Charles Darwin (who believed that man had evoked from very simple forms to the present human) had on Spencer. The word "levels" in the second paragraph means ______.
Most of us trade money for entertainment. Movies, concerts and shows are enjoyable but expensive. (78) If you think that you can’t have a good time without spending a lot of money, read on. A little resourcefulness and a few minutes of newspaper- scanning should give you some pleasant surprises. People may be the most interesting show in a large city. Stroll through busy streets and see what everybody else is doing. (79) You will probably see people from all over the world; you will certainly see people of every age, size, and shape, and you’ II get a free fashion show, too. Window - shopping is also a safe sport - if the stores are closed. Check the listings in your neighborhood paper. Local colleges or schools often welcome the public to hear an interesting speaker or a good debate. The film or concert series at the local public library probably won’t cost you a penny. Be sure to check commercial advertisements too. A flea market can provide hours of pleasant browsing. Perhaps you can find a free cooking or crafts demonstration in a department store. Plan ahead for some activities. It is always more pleasant not to have people in front of you in a museum or at a zoo. You may save some money, too, since these places often set aside one or two free admission days at slow times during the week. Pretend that you are a tourist from time to time, and get to know your city all over again including the indispensable sights that people travel miles to see. If you feel like taking an interesting walk, find a free walking tour, or plan one yourself. You will see your city in a new perspective once you know more about its history or its architectural treasures. With imagination and a spirit of adventure you can quite easily find good entertainment at no cost at all. "... one or two free admission days at slow time." means ______.
微信支付 
支付宝支付