单词拼写(首字母已给出)
【小题1】This song always r________ me of my childhood.
【小题2】When I was young, I lived in a beautiful town s_________ by trees and flowers.
【小题3】What a___________ for his failure?
【小题4】He looks pale and weak today. It is o________ that he is ill.
【小题5】In order to keep healthy, you should eat a b_________ diet.
【小题6】This is a non-smoking area, so no one is p_______ smoking here.
【小题7】Although the boy is only four, he has a g_______ for music.
【小题8】What he said at the meeting i_________ everyone present deeply.
【小题9】Reading is useful and you can b________ a lot from it.
【小题10】A friend in need is a friend i_______.
小球做匀速圆周运动，则小球按如图所示的方式在墙上形成的投影的运动是简谐运动，这是可以证明的结论．证明一个运动是简谐运动的一个判定式是a=-kx，a为作简谐运动物体的加速度．假如，此质点的质量是m，圆半径是R，匀速圆周运动的线速度大小是v，则反映此投影是简谐运动的式子a=-kx中的k是多少？
