The not necessarily well-prepared student sat in his life scienceclassroom staring at a question on the final exam paper. The questiondirected: “Give four advantages of breast milk.” What to write? Hesighed, and began to scribble whatever came into his head, hoping forthe best:1. No need to boil.2. Cats can’t steal it.3. Available whenever necessary.So far so good – maybe. But the exam demanded a four-part answer. Again, what to write? Once more, he sighed. He frowned. He scowled,then sighed again. But suddenly, he brightened. He grabbed his pen,and triumphantly, he scribbled his definitive answer:4. Available in attractive containers.