扁平疣的病原体
A．双链DNA病毒
B．单链DNA病毒
C．RNA病毒
D．副黏病毒
E．核病毒
参考答案：A
具有细胞结构而没有核膜的一组生物是[ ]
A．噬菌体、乳酸菌
B．细菌、蓝藻
C．变形虫、草履虫
D．蓝藻、酵母菌
Professor James will give us a lecture on the Western culture, but when and where _______ yet.[ ]
A. hasn’t been decided
B. haven’t decided
C. isn’t being decided
D. aren’t decided
