Alex never opens the front door. When someone knocks on the front door, Alex says, "Who is it?" But he does not open the door. His parents told him to keep the door closed. His parents want him to be safe. He will be safe if he doesn't open the door. Yesterday someone knocked on the front door. "Who is it?" Alex asked. "It's the mailman," the person said. "I cannot open the door,"Alex said. "Okay, I will come back tomorrow," the mailman said. "Goodbye," Alex said. Alex is a good boy. He listens to his parents. He doesn't open the door for any person