具有氨基醚结构
A．盐酸苯海拉明B．马来酸氯苯那敏C．盐酸赛庚啶D．奥美拉唑E．盐酸雷尼替丁
参考答案：A
The present system no longer meets the changing needs of our customers; we have to make a(n) ____
management system.[ ]
A. contradictory
B. endless
C. flexible
D. concrete
跳高运动员起跳时总是用力向下蹬地，利用的物理知识是 。
