阅读小天地，读一读，选一选。

      Bob, Jack and Tom are friends. They like different kinds (种类) of food. Bob likes meat. He always eats

meat. Sometimes he eats cabbage. He never eats peas. Jack usually eats onions and soup. He sometimes eats

meat. He doesn't like eggs. He never eats eggs. Tom likes ice cream. He always eats ice cream. He sometimes

eats carrots and peas. He never eats soup.

1. Bob, Jack and Tom are _____________.

A. brothers

B. friends

C. sisters

2. Bob always eats _____________.

A. cabbage

B. soup

C. meat

3. Jack doesn't like _____________.

A. eggs

B. soup

C. ice cream

4. Tom doesn't like _____________.

A. peas

B. eggs

C. soup

5. Tom always eats _____________.

A. meat

B. ice cream

C. eggs

从生命系统的结构来分析，下列结构属于哪个层次？

①受精卵 ②树叶 ③心脏 ④一块骨骼肌 ⑤红细胞 ⑥植物的形成层 ⑦一个酵母菌 ⑧池塘中的所有鲤鱼⑨某山上的所有生物 ⑩一片森林中所有红松 一个池塘中的一切 一只小白鼠 消化系统

A．细胞：_______；B．组织：_______；C．器官：______；D．系统：______；E．个体：______；F．种群：________；G．群落：_________；H．生态系统：________。