C

    My friend John has got a restaurant(餐馆) in a big city. It is near a supermarket. He gets ten robots for the restaurant. Each robot costs (价钱为) 20,000 yuan. The restaurant is not big, but very popular（受欢迎的）. Now more and more people come here for dinner.

    The robots have different jobs in the restaurant. Two robots cook different kinds of food; one washes the dishes; one cleans the floor and the others give food to the guests (客人).

    Although robots do most of the jobs in the restaurant, John is still very busy. He must do many things to keep the robots working well. Luckily, John is good at studying robots and he knows robots very well. I think in the future, there will be a lot of robot themed restaurants (机器人主题餐厅) around the world.

希望小学对1999年入学的学生连续五年进行视力追踪检查，其中近视的人数见下表．

①近视人数哪年最多，哪年最少，相差多少人．

②近视人数的变化有怎样的趋势？

③预测一下2004年近视人数的状况如何？

①通过民族文化的寻根活动，弘扬家国情怀，增强文化自信

②通过家风文化价值的发现，重塑家庭观念，传递人间温情

③用不同的中国人家庭故事，代言中华家风，传播科学知识

④通过文化人物的言传身教，展现家风主题，闪耀文化力量

请在图中画出光进入玻璃和离开玻璃后的径迹（注意标出法线）．