diff --git a/include/effective_c++/Clock.h b/include/effective_c++/Clock.h
index 58644f1..ec3fdfa 100644
--- a/include/effective_c++/Clock.h
+++ b/include/effective_c++/Clock.h
@@ -17,7 +17,10 @@ namespace effective {
 
   private:
     virtual std::string onTick() const;
-    int tick_frequency;
+    //> 成员变量初始化的顺序为：先声明时初始化，然后初始化列表初始化，最后构造函数初始化。
+    //> 如果调用了一个类的默认构造函数，那么这个变量的值则来自于声明初始化。如果声明时
+    //> 未初始化，则此变量值为该类型的默认值。
+    int tick_frequency{1};
     bool is_running{true};
   };
 }  // namespace effective
diff --git a/include/effective_c++/home/home.h b/include/effective_c++/home/home.h
index 3a32ec8..9d7d22a 100644
--- a/include/effective_c++/home/home.h
+++ b/include/effective_c++/home/home.h
@@ -50,7 +50,10 @@ namespace effective {
     std::string boardcastAddress() const;
 
   protected:
-    std::string address_;
+    //> 成员变量初始化的顺序为：先声明时初始化，然后初始化列表初始化，最后构造函数初始化。
+    //> 如果调用了一个类的默认构造函数，那么这个变量的值则来自于声明初始化。如果声明时
+    //> 未初始化，则此变量值为该类型的默认值。
+    std::string address_ = "";
 
   private:
     //> doHealthValue是private级别，派生类访问不到，但是派生类可以重写属于自己的函数。
diff --git a/test/source/home_factory_test.cpp b/test/source/home_factory_test.cpp
index 73d46c8..ea65322 100644
--- a/test/source/home_factory_test.cpp
+++ b/test/source/home_factory_test.cpp
@@ -12,4 +12,9 @@ TEST_CASE("HomeFactory") {
   CHECK(one_cave->GetAddress("decorate ") == "decorate ParaMountain");
   CHECK(one_cave->GetAddress() == "ParaMountain");
   CHECK(one_cave->boardcastAddress() == "This from home begin send address Tick begin My cave address is : ParaMountainMy cave address is : ParaMountainMy cave address is : ParaMountainend.");
+  auto one_nest = home_factory.makeHome("Nest");
+  CHECK(one_nest->draw(2) == "let paint the house as Blue");
+  CHECK(one_nest->healthValue() == "before check health of full Nest after.");
+  CHECK(one_nest->GetAddress("decorate ") == "decorate ");
+  CHECK(one_nest->boardcastAddress() == "This from home begin send address Tick begin My nest address is : My nest address is : My nest address is : end.");
 }