根据句意和汉语注释,在空格内写出单词的正确形式。

1. Are there any ___________ (图书馆) in your new school?

2. Simon feeds his __________ (可爱的) cats and dogs every day.

3. Everyone in my family likes __________ (游泳).

4. His grandfather is a __________ (有礼貌的) man.

5. He is a good student. He sings very _________ (好).

下列有关真核生物基因的说法，正确的是（）

①基因是有遗传效应的DNA片段

②基因的基本单位是脱氧核糖核苷酸

③基因存在于细胞核、核糖体等结构

④基因的分子结构首先由摩尔根发现

⑤DNA分子每一个片段都是一个基因

A.两种

B.三种

C.四种

D.五种