题目

Everybody is afraid of something. That’s what more than 1,700 kids told us when we asked them about fears and scary(害怕的) things. We gave kids a list of 14 scary things and asked which one frightened them most. Here are the top 5 answers from our survey: ① Scary movies and TV shows; ② Scary dreams; ③ Thunderstorms, hurricanes (飓风), and other horrible weather; ④ War and terrorism (恐怖行动); ⑤ Sounds heard at night.But not everyone is afraid of the same thing. And what makes one person scared can be of no big deal for someone else. Plenty of kids said their biggest fear（8分）下图表示细胞内某些有机物的元素组成和功能关系，其中A、B代表元素，Ⅰ、Ⅱ、Ⅲ是生物大分子， X、Y、Z、P分别为构成生物大分子的基本单位，请回答下列问题：? （1）Ⅰ在小麦种子中主要是指           ，在动物细胞中主要是指           。? （2）物质Z是              ，其形成的Ⅲ可用甲基绿—吡罗红混合染液染成       色。 （3）物质P是              ，其中，在人体内细胞中不能合成、需要从食物中获取的P叫做            。 （4）物质Y是              。物质Ⅱ的分子结构的特异性是由Y的                   决定的。