题目

下列动物行为中，属于先天性行为的是             （  ） A．小狗算算术           B．刚出生的小猪吃奶C．大山雀喝牛奶          D．海豚表演顶球、跳跃 答案：B Much to his surprise, he invited only twenty friends to the dinner, but ____ came. A.twice as many as 　　　　　 B. as many as twice 　C. twice as many 　　　　　　 D. twice more than