diff --git a/SoftwareDesign/Code/1-2/main.cpp b/SoftwareDesign/Code/1-2/main.cpp
index 7ff7b23..d0e1703 100644
--- a/SoftwareDesign/Code/1-2/main.cpp
+++ b/SoftwareDesign/Code/1-2/main.cpp
@@ -40,4 +40,5 @@ int main()
               << c.at(0, 1) << " " << c.at(1, 1) << " " << c.at(2, 1) << std::endl;
 
     return 0;
-}
\ No newline at end of file
+}
+
diff --git a/SoftwareDesign/Code/1-3b/main.cpp b/SoftwareDesign/Code/1-3b/main.cpp
new file mode 100644
index 0000000..5f6d869
--- /dev/null
+++ b/SoftwareDesign/Code/1-3b/main.cpp
@@ -0,0 +1,15 @@
+#include <iostream>
+#include "../inc/matrix.hpp"
+
+void print_element(const MatBase<double> &m, int x, int y)
+{                                         // 注意参数是基类
+    std::cout << m.at(x, y) << std::endl; // 调用虚函数所定义的接口
+}
+
+int main()
+{
+    Matrix<double> a(2, 2, 9.0);
+    Matrix<double> b(2, 2, 7.0);
+    print_element(a, 0, 0); // 输出 Mat2x2 变量 a 的第一个元素，注意输入是派生类
+    print_element(b, 0, 0); // 输出 Matrix 变量 b 的第一个元素，注意输入是派生类
+}
\ No newline at end of file
diff --git a/SoftwareDesign/Code/2-1/.gitignore b/SoftwareDesign/Code/2-1/.gitignore
deleted file mode 100644
index e69de29..0000000
diff --git a/SoftwareDesign/Code/workspace.code-workspace b/SoftwareDesign/Code/workspace.code-workspace
index 3a7c375..380db66 100644
--- a/SoftwareDesign/Code/workspace.code-workspace
+++ b/SoftwareDesign/Code/workspace.code-workspace
@@ -46,7 +46,34 @@
 			"ostream": "cpp",
 			"typeinfo": "cpp",
 			"ctime": "cpp",
-			"iomanip": "cpp"
+			"iomanip": "cpp",
+			"bit": "cpp",
+			"chrono": "cpp",
+			"codecvt": "cpp",
+			"compare": "cpp",
+			"complex": "cpp",
+			"concepts": "cpp",
+			"condition_variable": "cpp",
+			"cstring": "cpp",
+			"list": "cpp",
+			"map": "cpp",
+			"set": "cpp",
+			"unordered_set": "cpp",
+			"functional": "cpp",
+			"iterator": "cpp",
+			"numeric": "cpp",
+			"random": "cpp",
+			"ratio": "cpp",
+			"source_location": "cpp",
+			"future": "cpp",
+			"mutex": "cpp",
+			"numbers": "cpp",
+			"semaphore": "cpp",
+			"stop_token": "cpp",
+			"thread": "cpp",
+			"cinttypes": "cpp",
+			"valarray": "cpp",
+			"variant": "cpp"
 		},
 		"commentTranslate.hover.enabled": true
 	}