决定列车垂直振动大小最基本的因素是（）。
参考答案：承载弹簧的静绕度
Which of the following is NOT one of the conditions that must be met for a trade to be considered an arbitrage()
A. There is no risk.
B. There are no commissions.
C. There is no initial investment and there is a guaranteed profit.
请论述零售企业对门店商品划分组群的常用模式？
