diff --git a/LinqStudy.Test/LinqToObject/GroupTest.cs b/LinqStudy.Test/LinqToObject/GroupTest.cs
index c511165..732400d 100644
--- a/LinqStudy.Test/LinqToObject/GroupTest.cs
+++ b/LinqStudy.Test/LinqToObject/GroupTest.cs
@@ -1,10 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
-
 using System.Linq;
-
 using Xunit;
-
 using LinqStudy;
 
 namespace LinqStudy.Test.LinqToObject
@@ -76,7 +73,7 @@ namespace LinqStudy.Test.LinqToObject
         }
     
         /// <summary>
-        ///  重载：keySelector， comparer
+        ///  重载2：keySelector， comparer
         ///  key：是引用类型，使用自定义比较器
         /// </summary>
         [Fact]
@@ -91,16 +88,20 @@ namespace LinqStudy.Test.LinqToObject
 
             };
 
-            var group = peoples.GroupBy(p=>p.Hometown,new HometownEqualityComparer());
+            var group = peoples.GroupBy
+            (
+                p=>p.Hometown,
+                new HometownEqualityComparer()
+            );
 
-            var groupFirstNames=group.First().Select(q=>q.Name).ToList();
+            var actual=group.First().Select(q=>q.Name).ToList();
             var expected=new List<string>(){"河南周口人","俺河南周口哩"};
 
-            Assert.Equal(expected,groupFirstNames);
+            Assert.Equal(expected,actual);
         }
 
         /// <summary>
-        ///  重载：keySelector， elementSelector
+        ///  重载3：keySelector， elementSelector
         ///  key：是引用类型，使用自定义比较器
         /// </summary>
         [Fact]
@@ -115,15 +116,20 @@ namespace LinqStudy.Test.LinqToObject
 
             };
 
-            var group = peoples.GroupBy(p=>p.Id,t=>t.Name).ToList();
+            var group = peoples.GroupBy
+            (
+                p=>p.Id,
+                t=>t.Name
+            )
+            .ToList();
 
-            var groupFirstNames=group[2].FirstOrDefault();
+            var actual=group[2].FirstOrDefault();
             var expected="上海松江人";
 
-            Assert.Equal(expected,groupFirstNames);
+            Assert.Equal(expected,actual);
         }
         /// <summary>
-        /// 重载：keySelector elementSelector comparer
+        /// 重载4：keySelector elementSelector comparer
         /// </summary>
         [Fact]
         public void GroupBy_keySelector_elementSelector_comparer_Test()
@@ -137,14 +143,23 @@ namespace LinqStudy.Test.LinqToObject
 
             };
 
-            var group = peoples.GroupBy(p=>p.Hometown,t=>t.Name,new HometownEqualityComparer()).ToList();
+            var group = peoples.GroupBy
+            (
+                p=>p.Hometown,
+                t=>t.Name,
+                new HometownEqualityComparer()
+            )
+            .ToList();
 
-            var groupFirstNames=group[2].FirstOrDefault();
+            var actual=group[2].FirstOrDefault();
             var expected="上海松江人";
 
-            Assert.Equal(expected,groupFirstNames);
+            Assert.Equal(expected, actual);
         }
         
+        /// <summary>
+        ///  重载5：keySelector resultSelector
+        /// </summary>
         [Fact]
         public void GroupBy_keySelector_resultSelector_Test()
         {
@@ -157,12 +172,103 @@ namespace LinqStudy.Test.LinqToObject
 
             };
 
-            var group = peoples.GroupBy(p=>p.Id, (key,teacher) => teacher.Select(t=>t.Name)).ToList();
+            var group = peoples.GroupBy
+            (
+                p=>p.Id, 
+                (key,teacher) => teacher.Select(t=>t.Name)
+            )
+            .ToList();
+
+            var lastGroupItem=group[2].FirstOrDefault();
+            var expected="上海松江人";
+
+            Assert.Equal(expected,lastGroupItem);
+        }
+
+        /// <summary>
+        ///  重载6：keySelector resultSelector
+        /// </summary>
+        [Fact]
+        public void GroupBy_keySelector_resultSelector_comparer_Test()
+        {
+            List<Teacher> peoples=new List<Teacher>()
+            {
+                new Teacher(){Id=1, Name="河南周口人", Hometown=new Hometown(){Province="河南", City="周口"}},
+                new Teacher(){Id=1, Name="俺河南周口哩", Hometown=new Hometown(){Province="河南",City="周口"}},
+                new Teacher(){Id=3, Name="上海宝山人", Hometown=new Hometown(){Province="上海",City="宝山"}},
+                new Teacher(){Id=4, Name="上海松江人", Hometown=new Hometown(){Province="上海",City="松江"}},
+            };
+
+            var group = peoples.GroupBy
+            (
+                p=>p.Hometown, 
+                (key,teacher) => teacher.Select(t=>t.Name),
+                new HometownEqualityComparer()
+            )
+            .ToList();
+
+            var lastItem=group[2].FirstOrDefault();
+            var expected="上海松江人";
+
+            Assert.Equal(expected, lastItem);
+        }
+
+        /// <summary>
+        ///  重载7：keySelector elementSelector resultSelector
+        /// </summary>
+        [Fact]
+        public void GroupBy_keySelector_elementSelector_resultSelector_Test()
+        {
+            List<Teacher> peoples=new List<Teacher>()
+            {
+                new Teacher(){Id=1, Name="河南周口人", Hometown=new Hometown(){Province="河南", City="周口"}},
+                new Teacher(){Id=1, Name="俺河南周口哩", Hometown=new Hometown(){Province="河南",City="周口"}},
+                new Teacher(){Id=3, Name="上海宝山人", Hometown=new Hometown(){Province="上海",City="宝山"}},
+                new Teacher(){Id=4, Name="上海松江人", Hometown=new Hometown(){Province="上海",City="松江"}},
+            };
+
+            var group = peoples.GroupBy
+            (
+                p=>p.Hometown.Province+p.Hometown.City,
+                (teacher)=> new {Id= teacher.Id,name=teacher.Name, Province=teacher.Hometown.Province},
+                (key, result) => result.Select(q=>q.Province)
+            )
+            .ToList();
 
-            var groupFirstNames=group[2].FirstOrDefault();
+            var lastItem=group[2].FirstOrDefault();
             var expected="上海松江人";
 
-            Assert.Equal(expected,groupFirstNames);
+            Assert.Equal(expected, lastItem);
+        }
+
+        /// <summary>
+        ///  重载8：keySelector elementSelector resultSelector
+        /// </summary>
+        [Fact]
+        public void GroupBy_keySelector_elementSelector_resultSelector_comparer_Test()
+        {
+            List<Teacher> peoples=new List<Teacher>()
+            {
+                new Teacher(){Id=1, Name="河南周口人", Hometown=new Hometown(){Province="河南", City="周口"}},
+                new Teacher(){Id=1, Name="俺河南周口哩", Hometown=new Hometown(){Province="河南",City="周口"}},
+                new Teacher(){Id=3, Name="上海宝山人", Hometown=new Hometown(){Province="上海",City="宝山"}},
+                new Teacher(){Id=4, Name="上海松江人", Hometown=new Hometown(){Province="上海",City="松江"}},
+            };
+
+            var group = peoples.GroupBy
+            (
+                p=>p.Hometown,
+                (teacher)=> new {Id= teacher.Id,name=teacher.Name, Province=teacher.Hometown.Province},
+                (key, result) => result.Select(q=>q.Province),
+                new HometownEqualityComparer()
+
+            )
+            .ToList();
+
+            var lastItem=group[2].FirstOrDefault();
+            var expected="上海";
+
+            Assert.Equal(expected, lastItem);
         }
     }
 }
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