（1）编写一个程序实现如下功能：有4名学生，每个学生信息包含学号、姓名、数学成绩、英语成绩、C语言成绩和三门课程的总分，并对数据进行输入和输出（程序以文件名sy8_7.c存盘）。

（2) 编写一个程序实现如下功能：定义一个点的结构数据类型，实现下列功能：

①为点输入坐标值。

②求两个点中点坐标。

③求两点间距离。

(程序以文件名sy8_8.c存盘

（3）编写一个程序实现如下功能：建立一个单链表，每个结点数据要有职工号、工资。用一个creat函数来建立链表，用list函数输出数据（数据自定）(程序以文件名sy8_9.c存盘)。-(1) Write a program to achieve the following functions: There are four students, each student information includes student number, name, math, English, C language course grades and three scores, and the data for input and output ( procedures to save the file name sy8_7.c). (2) Write a program to achieve the following functions: structure defines the data type of a point, to achieve the following functions: ① input coordinate value for the point. ② Find the midpoint coordinates of the two points. ③ the distance between two points. (Filename sy8_8.c procedures to save (3) Write a program to achieve the following functions: to establish a single linked list, each node data have number of workers, wages with a creat function to create the list, with the list function output data ( Data Custom) (file name sy8_9.c procedures to save).