练习材料：
L2-1 Spare that spider不要伤害蜘蛛
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 fraction of the number destroyed by spiders．Moreover, unlike some of the other insect eaters, spiders never do the least harm to us or our belongings.
Spiders are not insects, as many people think, nor even nearly related to them．One can tell the difference almost at a glance, for a spider always has eight legs and an insect never more than six.
应用配置：L0+L4
知识笔记： devour/ owe/ insect/
练习感悟：用时46分。多花了些时间在雕琢发音。今天的语感不错。
