地铁与轻轨划分的原则（）。
A、运行列车的重量
B、轨道承受的荷重
C、运行速度的快慢
参考答案：B
下列各项，再生障碍性贫血的发病脏腑是（）
A.心、肝、脾、肾
B.肺、肝、脾、肾
C.心、肝、脾、肺
D.心、肺、脾、肾
E.心、肝、肺、肾
(66) is defined as the buying and selling of products and services over the Internet. It had included the handling of purchase (67) and funds transfers over computer networks from its inception.
A．Electronicmail
B．Searchengine
C．Multimedia
D．Electroniccommerce
