下列句中划线词语的解释，最准确的一项是 （        ）

    Jack is not old, but he doesn't have much hair. His wife Alice has thick(厚的)and black hair.

    They have a daughter(女儿). Her name is Kitty. And Kitty is five years old. 0ne day, Jack is reading a book in his room. Kitty looks at her father for a long time and says to her mother,“Why does father have so little hair?”“He has little hair because(因为)he thinks a lot. He is a very clever(聪明的)man. ”Alice says with a smile(微笑).

分类单位越大，所包含的种类越少

下面句子中有两个错别字，请改正后用正楷字将整个句子抄写在横线上。

宏扬长征精神，磨少年品质。