Welcome to our introductory course on nutrition. This first lecture will center on a very valuable member of the beam family. The soy bean (大豆)is a highly nutritious bean which also can serve as a meat substitute. Some people call soy beans incredible. Let me give you some examples of why the soy bean is so special. First of all, when it is made into meal, it enhances animal feed. Secondly, as soy four it similarly enriches the baked goods we humans eat. Thirdly, as soy chips or flakes, it’s often included in cereals. And lastly, In some countries, for example, China. The soy beam is processed into virtually all fresh milk consumed there. It is also the basic ingredient of textured vegetable protein which brings a meat-like taste and feel to vegetarian dishes. For many years soy bean were thought of in the United States only as a commercial agricultural crop. Now, however, the soy bean is being, raised in backyard gardens, It’s easy to grow and, as I have pointed but before ,beneficial in many ways. In the past soy beans were grown in the united states mainly（）

A. as the material of tofu(豆腐)
B. for backyard decoration
C. as a vegetable in most backyard gardens
D. as a commercial agricultural crop