Scientific discoveries have changed man’s life a great deal during the past century. First of all, they have greatly improved material well-being in several areas of life. In the field of medicine, cures for life threatening diseases have enabled people to live longer. In communication, the telephone and e-mail have made it possible for us to communicate with anyone in the world without leaving our homes or offices. Advances in transportation allow businessmen to fly across the ocean in the morning and return home the same evening. Space technology has put men on the moon. More efficient ways of using available resources, such as coal and solar power, have been explored.
Scientific discoveries have also changed man’s moral atmosphere. Ethical (伦理的) issues are raised by these discoveries. Should we keep a terminally ill person alive through drugs and machines or should we allow him to die in dignity? With advances in transportation had come the problem of pollution for nearly every major city in the world. If cities become uninhabitable, then such technical advances may come with too great a price to pay. Many people also question the wisdom of sending men to the moon when there are urgent problems that have not been solved on earth. During future years, increasing attention must be given to the moral as well as the practical applications of science.
小题1:Scientific discoveries have improved man’s life in several fields. Which of the following is not mentioned in the passage?
A．medicine
B．communication and transportation
C．education
D．space technology小题2: Which of the following statements is true according to the passage?
A．Scientific discoveries have only changed man’s moral atmosphere.
B．Scientific discoveries have only changed man’s material well-being.
C．Scientific discoveries have helped people find efficient ways of using available resources.
D．Men are sent to the moon because there are urgent problems that have not been solved on earth.小题3:At the end of the passage the author says that increasing attention must be given to _________.
A．the moral applications of science
B．the practical applications of science
C．urgent problems on the earth
D．both A and B小题4:The best title for the passage is __________.
A．Science discoveries
B．Science and daily life
C．Advances in transportation
D．City pollution
时质点5的运动方向向下
质点7的加速度方向向上
时质点5运动的路程为3S
时质点5运动的路程就必需知道该质点已运动多少时间即多少周期再根据一个周期内质点通过的路程为4A求解；要求t=T时质点9运动的方向需知道该时刻质点9已运动的时间从而确定其运动的方向．
，质点1从平衡位置运动到波峰，位移为S，则振幅A=S，由于后一个质点重复前一个质点的振动，由于质点1开始振动时是从平衡位置开始向上振动，故质点5，开始振动时也是由平衡位置开始向上振动．故A错误．
λ，则质点1到质点7为
λ，所以波从质点1传到质点7所需时间为
时质点7已振动
T，即质点7在从平衡位置向正的最大位置运动过程中，根据a=-
故加速度方向向下．故B错误．
×4S=2S，故C错误．