在下列系统中，最具有生物多样性的生态系统是[ ]
A．森林生态系统
B．草原生态系统
C．湿地生态系统
D．城市生态系统
答案：A
根据图片提示填出所缺单词。
1. I like best. It' s snowy. I can make snowmen.
2. She wants to write a to her penfriend next week.
3. Look, No. 7 bus is near our school.
4. My cousin would like a tree as a present.
5. His grandpa needs a pair of when he reads newspapers.
阿托品解救有机磷中毒的机理为：（）
A.促使有机磷失活
B.竞争胆碱能烟碱样受体
C.竞争胆碱能毒蕈烟碱样受体
D.抑制胆碱能毒蕈烟碱样受体
E.抑制胆碱能烟碱样受体
best. It' s snowy. I can make snowmen. 
to her penfriend next week. 
is near our school. 
tree as a present. 
when he reads newspapers.