哪种病毒可导致急性病毒感染的迟发并发症（）
A.风疹病毒
B.麻疹病毒
C.巨细胞病毒
D.单纯疱疹病毒
E.乙脑病毒
参考答案：B
There is a new problem involved in the popularity of private cars ________ road conditions need ________.
A．that；to be improved
B．which; to be improved
C．where；improving
D．when；improving
物流信息有哪些功能及特征？
