The doctor strongly recommended that he ________ a holiday.

A．would take

B．took

C．had taken

D．take

由于称重传感器外壳接地点与供桥电源机壳接地点不同，所引进的干扰叫（）。

A.串模干扰

B.共模干扰

C.电磁干扰

D.电波干扰