影响群落结构的因素有______、______、______和岛屿化等。
参考答案：生物因素 空间异质性 干扰
______ that he could not speak for a long time.
A．so frightened was he
B．so frightened he was
C．was he so frightened
D．frightened was he
内部控制测试中的抽样风险包括（）。
A.信赖过度风险
B.信赖不足风!段
C.谈受风险
D.误据风险
E.检查风险
