不同厂家生产的或同一厂家不同一批生产的电雷管（）使用。

A.可以掺混

B.不得掺混

C.可以少量掺混

A project manager needs to assess qualify on the project. To do so, he wants to measure the height of each table produced. However, that would be too expensive. In this case, it would be BEST to use （）.

A．benchmarking

B．a sample

C．a control chart

D．a Pareto diagram