diff --git a/Arduino_Exercises/Exercise10/Exercise10.ino b/Arduino_Exercises/Exercise10/Exercise10.ino
index 50b6def..427ecee 100644
--- a/Arduino_Exercises/Exercise10/Exercise10.ino
+++ b/Arduino_Exercises/Exercise10/Exercise10.ino
@@ -37,17 +37,13 @@ void loop()
   if (digitalRead(SW1_PIN) == LOW) {
     flag = 1;
     delay(30);
-    while (digitalRead(SW1_PIN) == LOW) {
-      // pass
-    }
+    while (digitalRead(SW1_PIN) == LOW) continue;
     delay(30);
   }
   if (digitalRead(SW2_PIN) == LOW) {
     flag = 0;
     delay(30);
-    while (digitalRead(SW2_PIN) == LOW) {
-      // pass
-    }
+    while (digitalRead(SW2_PIN) == LOW) continue;
     delay(30);
   }
   if (flag == 1) {
diff --git a/Arduino_Exercises/Exercise19/Exercise19.ino b/Arduino_Exercises/Exercise19/Exercise19.ino
index 55b1d52..b7cecb3 100644
--- a/Arduino_Exercises/Exercise19/Exercise19.ino
+++ b/Arduino_Exercises/Exercise19/Exercise19.ino
@@ -112,9 +112,7 @@ void loop()
   //マーカーを検出?
   if (line_signed == 1) {
     if (adc_read_value(PB_0, 10) > 80) {
-      while (adc_read_value(PB_0, 10) > 60) {
-        // pass
-      }
+      while (adc_read_value(PB_0, 10) > 60) continue;
       counter++;
       if (counter > 1) {
         digitalWrite(LED_PIN, LOW);
@@ -134,9 +132,7 @@ void loop()
     }
   } else {
     if (adc_read_value(PB_0, 10) < 30) {
-      while (adc_read_value(PB_0, 10) < 45) {
-        // pass
-      }
+      while (adc_read_value(PB_0, 10) < 45) continue;
       counter++;
       if (counter > 1) {
         digitalWrite(LED_PIN, LOW);
diff --git a/Arduino_Exercises/Exercise6/Exercise6.ino b/Arduino_Exercises/Exercise6/Exercise6.ino
index 29cf5ee..2b6e288 100644
--- a/Arduino_Exercises/Exercise6/Exercise6.ino
+++ b/Arduino_Exercises/Exercise6/Exercise6.ino
@@ -35,9 +35,7 @@ void loop()
     digitalWrite(LED_PIN, HIGH);
     count++;
     //   delay(30);
-    while (digitalRead(SW1_PIN) == LOW) {
-      // pass
-    }
+    while (digitalRead(SW1_PIN) == LOW) continue;
     //   delay(30);
   } else {
     digitalWrite(LED_PIN, LOW);
diff --git a/Arduino_Exercises/Exercise7/Exercise7.ino b/Arduino_Exercises/Exercise7/Exercise7.ino
index 4a4489b..f58fe58 100644
--- a/Arduino_Exercises/Exercise7/Exercise7.ino
+++ b/Arduino_Exercises/Exercise7/Exercise7.ino
@@ -37,9 +37,7 @@ void loop()
       count++;
     }
     delay(30);
-    while (digitalRead(SW1_PIN) == LOW) {
-      // pass
-    }
+    while (digitalRead(SW1_PIN) == LOW) continue;
     delay(30);
   } else {
     digitalWrite(LED_PIN, LOW);