Shakespeare's plays fall into three genres: comedies, tragedies, and __________

A big improvement in photography, based on Fox Talbot's work, was __________

A. keeping light out of the process B. taking a long time for exposures C. the development of a means of creating multiple copies of an image D. the zoom lens

The Roman emperors who came to power in the third century generally obtained imperial power because they had the support of

A) ?the Roman citizens. B) ?the provincial consuls. C) ?the Senate. D) ?the military.