When she saw me, she did't stop. She just walked _____. [ ]
A. from
B. on
C. to
D. up
B
何谓变形缝
运输需求的波动性是指运输需求量在( )上呈现出的不均衡状态。
A.线路分布 B.时间分布C.地区分布 D.运输方式分布