A little boy named Bobby entered his first science fair in second grade. Because his Mom has a green thumb, they decided to experiment with the growth of plants. He took two small green plants and placed one on a sunny windowsill and the other in a cardboard box. After a couple of weeks, Bobby checked on the two plants. The one on the windowsill had grown a couple of inches and had vibrant green leaves. The one in the box had actually grown a bit, but it had lost all of its green color, becoming alm…