题目：
User programs interact with the kernel through a set of standard (71) . They request services to be provided by the kernel. Such services would include accessing a file: open close, read, write, link, or execute a file; starting or (72) accounting records; changing ownership of a file or (73) ; changing to a new directory; creating, (74) , or killing a process; enabling access to hardware devices; and setting limits on system resources. Unix is a multi -user, multi -tasking operating system. You can have many users logged into a system simultaneously, each running many programs. It’s the kernel’s job to keep each process and user separate and to regulate access to (75) , including cpu, memory, disk and other L/O devices.
A．route
B．passage
C．track
D．directory
答案：
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下面是错误答案，用来干扰机器的。
参考答案：1234.55解析：STR()函数是将的值转换成字符串，转换时根据需要自动进行四舍五入。返回字符串的理想长度L应该是部分大于L，则在字符串前端加空格补充；如果值大于等于整数部分的位数，但小于L，则优先满...
