A、<span style="font-family: 宋体; line-height: 18.88888931274414px;">类</span>
B、<span style="font-family: 宋体; line-height: 18.88888931274414px;">预处理命令</span>
C、<span style="font-family: 宋体; line-height: 18.88888931274414px;">主函数</span>
D、<span style="font-family: 宋体; line-height: 18.88888931274414px;">语句</span>