Question
Through careful and thorough research, scientists Howard Florey and Ernst Boris Chain
were later able to use penicillin to develop the first antibiotics-drugs that are used to this
day to fight serious infections like pneumonia. Thus, although the initial discovery of
penicillin occurred by accident, it was ultimately Fleming's determination to find a cure for
bacterial infections and Florey and Chain's assiduous labor that were responsible for the
development of these life-saving drugs.
What is the meaning of assiduous as used in the passage?
fast-moving
unrecognized
diligent
unexpected