4.You ask your friend to close the door after your friend enter your room because the weather is so hot outside. square

The sentence is grammatically correct but could be improved for clarity and naturalness. Here are a few options:* **Option 1 (Most natural):** "Please close the door after you come in; it's really hot outside." This is concise and polite.* **Option 2 (Slightly more formal):** "Would you mind closing the door behind you? It's very hot outside." This is a more polite and indirect way of making the request.* **Option 3 (More direct):** "Close the door when you come in. It's hot outside." This is a more direct command, suitable for a close friend.The original sentence is understandable, but the phrasing "after your friend enter" is slightly awkward. The improved options use more natural English sentence structure.