He was diligent in the matter of temperature control.
They were diligent in the performance of their duties.
His range of reading was extensive, and he was a most diligent scholar and writer.
From his youth he was diligent in his studies and a great reader, and during his college life showed a marked talent for extemporaneous speaking.
There was a diligent inquiry and now most believe they acted on correspondence produced by Henry Woods on his own lawyer's request.