Algebra - Abstract algebra. 1  Abstract algebra extends the familiar concepts found in elementary algebra and arithmetic of numbers to more general concepts.
Choose the freshest looking lettuce for storing. Photo Credit anna1311/iStock/Getty Images. Romaine lettuce's high water content means there is no long-term preservation method suitable for making the lettuce last longer. Drying, canning and freezing all produce inedible results. For the best nutritional value, romaine lettuce is best served when it's fresh, green and crisp. Storing the lettuce in a refrigerator is the best option for preserving it, although there are a few other measures that can be taken to ensure romaine lettuce lasts as long as possible.
Baby-sized lettuce reaches maturity in about 4-6 weeks. Sow lettuce seeds every couple weeks to stretch out the harvest season. How to sow lettuce seed: Drop a small amount of lettuce seeds into one hand, then pinch the seed between your forefinger and thumb of the other hand. Drop the seeds thinly over the soil. Lettuce seeds are tiny, and they need light to germinate, so cover the seeds lightly -- never more than 1/4-in (.5 cm) -- with potting medium. Then, spray with water until thoroughly moist. Mist every morning to keep the medium moist at all times.