填空题
Welcome to our introductory course of nutrition, This first lecture will center on a very valuable member of the bean family, the soybean. The soybean is a highly nutritious bean, which also can serve as a meat substitute. Some people call soybeans incredible. Let me give you some examples of why the soybean is so special. First of all, when it is made into meal, it enhances animals feeds. Secondly, as soy flour, it similarly enriches the baked goods we humans eat. Thirdly, as soy chips or flakes, it is often included in cereals, and lastly, in some countries, (for example, China) the soybean is processed into virtually all fresh milk consumed there. It is also the basic ingredient of textured vegetable protein, which grinds a meat-like taste and feel to vegetarian dishes. For many years soybeans were thought of in the United States only as a commercial agricultural crop. Now, however, the soybean has been raised in backyard gardens, it is easy to grow and, I pointed out before, beneficial in many ways.
In the past, what was the main reason soybeans were grown in the United States