We felt amazed at the use　　the waste bottles.

A．they had made

B．they had made of

C．they had put

D．they had put to

水位—流量关系曲线低水放大图绘制的步骤有：①在原图曲线仔细读若干数据坐标（可借助放大镜观读）；②设计好放大图的坐标系和标度；③把读取的数据坐标点绘在放大图的坐标系；④参照原图趋势，绘出新的放大曲线。这些步骤的正确顺序是（）。

A、②③①④

B、①④②③

C、①④③②

D、②①③④