题目

 Sam is only one year old. He is too young __________.         A. to dress himself   B. get dressed    C. to put on       D. wear clothes 答案：A按照从小到大顺序进行分类的单位依次是（ ）A．种、纲、属、目、科、门、界B．种、纲、目、科、门、属、界C．科、种、纲、属、目、门、界D．种、属、科、目、纲、门、界