一. 主旨的定义 主旨 = 主题（KW ） + 方向（正负感情色彩） + 关系词（逻辑）一. 主旨的定义 Why you may wonder should spiders be our friends? Because they destroy so many insects, and insects include some of the greatest enemies of the human race. Insects would make it impossible for us to live in the world. They would devour all our crops, and kill our flocks and herds, if it were not for the protection we get from insect-eating animals. We owe a lot to the birds and beasts who eat insects but all of them put together kill only a fr
