根据句意及首字母提示填词。

1. —Yao Ming is tall and strong.

    —Yes. He is c _____.

2. The apple is g _____.Please give me a red one.

3. Here's a pencil. C_____ it yellow, please.

4. Look at that girl! She is in yellow d _____.

5. The teacher is old, but the students are y _____.

生物化石是证明生物进化的最主要直接证据，其根本原因是             

A．化石是保存在地层中的生物遗体、遗物或生活痕迹

B．化石能再现生物的结构和生物环境

C．各类不同生物化石在不同地层出现有一定的顺序

D．化石里的生物是现在生物的原始祖先