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.
There are five distinct types of lettuce: leaf (also called loose-leaf lettuce), Cos or romaine, crisphead, butterhead and stem (also called asparagus lettuce). Leaf lettuce, the most widely adapted type, produces crisp leaves loosely arranged on the stalk.Nearly every garden has at least a short row of leaf lettuce, making it the most widely planted salad vegetable. Cos or romaine forms an upright, elongated head and is an excellent addition to salads and sandwiches.t is a head lettuce that is also low in nutritional value and flavor. Because of its superior shipping qualities, iceberg has been most available which accounts for it popularity. The most abundant nutrient in iceberg lettuce is water.