diff --git a/c02_overview/fathm_ft.c b/c02_overview/fathm_ft.c
new file mode 100644
index 0000000..36a8ffb
--- /dev/null
+++ b/c02_overview/fathm_ft.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main(void)
+{
+    int feet, fathoms;
+
+    fathoms = 2;
+    feet = 6 * fathoms;
+    printf("There are %d feet in %d fathoms!\n", feet, fathoms);
+    printf("Yes, I said %d feet!\n", 6 * fathoms);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/c02_overview/first.c b/c02_overview/first.c
new file mode 100644
index 0000000..42a0f38
--- /dev/null
+++ b/c02_overview/first.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main(void)
+{
+    int num;
+    num = 1;
+
+    printf("I am a simple ");
+    printf("computer.\n");
+    printf("My favorite number is %d because it is first.\n", num);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/c02_overview/test01.c b/c02_overview/test01.c
new file mode 100644
index 0000000..7b5e7d5
--- /dev/null
+++ b/c02_overview/test01.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main(void)
+{
+    printf("Gustav Mahler\n");
+    printf("Gustav\nMahler\n");
+    printf("Gustav ");
+    printf("Mahler\n");
+    return 0;
+}
\ No newline at end of file
diff --git a/c02_overview/test03.c b/c02_overview/test03.c
new file mode 100644
index 0000000..d95a0fe
--- /dev/null
+++ b/c02_overview/test03.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main(void)
+{
+    int age = 40;
+    int days = age * 365;
+    printf("今年%d岁，活了%d多天了\n", age, days);
+    return 0;
+}
\ No newline at end of file
diff --git a/c02_overview/test04.c b/c02_overview/test04.c
new file mode 100644
index 0000000..dba5ce1
--- /dev/null
+++ b/c02_overview/test04.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+void jolly(void);
+void deny(void);
+
+int main(void)
+{
+    jolly();
+    jolly();
+    jolly();
+    deny();
+    return 0;
+}
+
+void jolly(void)
+{
+    printf("For he's a jolly good fellow!\n");
+}
+
+void deny(void)
+{
+    printf("Which nobody can deny!\n");
+}
\ No newline at end of file
diff --git a/c02_overview/two_func.c b/c02_overview/two_func.c
new file mode 100644
index 0000000..1f6e234
--- /dev/null
+++ b/c02_overview/two_func.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+void butler(void);
+
+int main(void)
+{
+    printf("I will summon the butler function.\n");
+    butler();
+    printf("Yes. Bring me some tea and writeable DVDs.\n");
+
+    return 0;
+}
+
+void butler(void)
+{
+    printf("You rang, sir?\n");
+}
\ No newline at end of file