Men could directly turn back to Greece and Rome for instruction, for correction, and for inspiration in the following fields of their work except ______.

A．Roman and Greek works were better than the those of medieval Christian church
B．Roman and Greek works were different from Medieval works
C．the Roman and Greek music became known
D．a lot of Roman and Greek works were discovered

A．plants that infest human habitations
B．the fact that bacteria are really vegetables
C．the growing stage of the bacteria as opposed to the dormant stage
D．the difficulty in classifying the . types of bacteria