Nginx怎么实现一个服务配置多个站点

server {
 listen 80;
 server_name a.ops-coffee.cn;

 location / {
 root /home/project/pa;
 index index.html;
 }
}

server {
 listen 80;
 server_name ops-coffee.cn b.ops-coffee.cn;

 location / {
 root /home/project/pb;
 index index.html;
 }
}

server {
 listen 80;
 server_name c.ops-coffee.cn;

 location / {
 root /home/project/pc;
 index index.html;
 }
}