//差集 去除相同，保留words1的内容
            var data1= (from v  in List1 select v).Except(from s  in List2  select s);
            //取同
            var data2= (from v in  List1 select v).Intersect(from s  in List2  select s);
            //合并 会去重
            var data3= (from v in List1 select v).Union(from s in List2 select s);
            //直连接 不会去重
            var data4= (from v in List1 select v).Concat(from s  in List2 select s);
            var data5= data4.Distinct()