矮桩式水尺在平坦岸坡设置时，两相邻桩顶的高差宜为（）m。
A、0.6～0.8
B、0.4～0..6
C、0.2～0.6
D、0.2～0.4
参考答案：D
超细干粉灭火剂100%粒径小于或等于（）的固体粉末灭火剂。
— Have you persuaded him?
— Yes.After some hours of discussion, I ________ to reason (说服) him into accepting the new plan.[ ]
A. had managed
B. would manage
C. manage
D. managed
