diff --git a/examples/MQ-7/MQ-7.ino b/examples/MQ-7/MQ-7.ino
index 7265a7a..a660cf1 100644
--- a/examples/MQ-7/MQ-7.ino
+++ b/examples/MQ-7/MQ-7.ino
@@ -49,7 +49,8 @@ void loop() {
   // Options, uncomment where you need
   //int lecture =  MQ7.readSensor("H2", true); // Return CH4 concentration
   //int lecture =  MQ7.readSensor("LPG", true); // Return LPG concentration
-  //int lecture =  MQ7.readSensor("CH4", true); // Return CO concentration
-  //int lecture =  MQ7.readSensor("CO", true); // Return Alcohol concentration
+  //int lecture =  MQ7.readSensor("CH4", true); // Return CH4 concentration
+  //int lecture =  MQ7.readSensor("CO", true); // Return CO concentration
   //int lecture =  MQ7.readSensor("Alcohol", true); // Return smoke concentration
+  delay(400);
 }