题目

Jack was playing ________ guitar while I was playing ________ soccer. A . a; / B . the; / C . /; the D . /; a 答案：B2. 人和动物的根本区别在于(   )   A. 制造工具方面   B. 使用工具方面   C. 渔猎和采集方面   D. 如何用火方面