轨距变化应和缓平顺，线路轨距变化率不得大于2‰。
参考答案：错
Most students can go to college for further in America. [ ]
A. education
B. information
C. science
D. technology
通常三环类抗抑郁药物的每天治疗剂量为（）
A.50mg
B.50～75mg
C.75～100mg
D.150～300mg
E.300～400mg
