What are some things you can do to make lettuce turn brown?
user
1. Over-watering lettuce 
2. Leaving the lettuce in a hot car 
3. Exposing it to direct sunlight for too long 
4. Keeping it on the counter before refrigerating
5. Placing it near sources of heat, like radios and lights
assistant
What are some things you can do to make lettuce turn brown?
user
Lettuce will turn brown if it is exposed to heat, air, or bright light, and if it is not washed or refrigerated promptly. Rusting can also cause lettuce to turn brown. To avoid this problem, store the lettuce in a cool dark place and make sure to wash it thoroughly before eating.
assistant
What are some things you can do to make lettuce turn brown?