英国学者李约瑟在《中国古代科学技术史》中写道：“从3世纪到13世纪，中国一直处于西方望尘莫及的科学地位，明清以后逐渐落后了。”
据此回答：

人生最美丽的补偿之一，就是人们真诚地帮助别人之后，也帮助了自己。这说明（   ）

    Ben and Jim are twin brothers. They are nine. They are pupils. They study in Yuxin Primary School. They are in the same class. Everyday they go to school and come back together.

    Their teacher, Mrs. Green, says to the pupils. Please write a composition (作文) 'My Mother'.

    Jim is a good boy. He writes the composition at home. But Ben plays football with his friends. The next day Mrs Green says to the class, “I read your compositions today. But two of yours are just the same.” Ben stands up and says, “Jim and I are twins. We have the same mother.”