— Do you think yesterday’s math problem was difficult?

— Yes, but            I worked it out.

A．hardly

B．easily

C．nearly

D．finally

引导婴幼儿对周围的（）感兴趣是帮助婴幼儿克服不良情绪情感及社会性的方法之一。

A.玩具

B.书籍

C.同龄伙伴

D.设施设备