参考答案:D
生态系统的自动调节能力有大有小,一般地说,生态系统的成分越单纯,营养结构越简单,自动调节能力就越小,抵抗力稳定性就越低。在北极苔原生态系统中,动植物种类稀少,营养结构简单,其中生产者主要是
第37题: [单项选择]Where does the conversation take place
A. In a supermarket.
B. In a cafeteria.
C. At a wedding ceremony.
D. At a cocktail party.
参考答案:A
答案解析:[听力原文]
W: How about some chicken supreme, then0 That looks quite nice.
M: OK. What do we need then
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