空间扩散由三种基本类型（）、等级扩散和重新区位扩散。
参考答案：传染扩散
I don't think teenagers should be allowed to do homework with friends, because they are ______. [ ]
A. not enough quiet
B. not quiet enough
C. too not quiet
D. enough not quiet
下列哪项不是乙脑常见的临床表现（）
A.病理征和脑膜刺激征
B.不同程度的意识障碍
C.重症出现呼吸衰竭
D.早期出现休克
E.持续高热
