She       some mistakes in her exercises the day before yesterday.

A． made

B． had made

C． has made

D． was making

钢管在出厂前应进行技术检验，填写证明报告书，检验的方法和内容是（）。

A.水压试验；

B.工艺性能试验：压扁、扩口、翻边；

C.几何尺寸检验：直径、壁厚、椭园度、直线度等；

D.化学成份检验和机械性能检验。