Alexander Fleming’s accidental discovery of penicillin in 1928 marked the beginning of modern antibiotics. He observed that a mold had contaminated a petri dish and killed the surrounding bacteria, leading scientists ______ the mold’s active substance into a life-saving medicine.
8
readingWhich choice completes the text so that it conforms to the conventions of Standard English?
A
isolating
B
isolated
C
to isolate
D
isolate
Correct Answer: C
Choice C is the best answer. The phrase "leading scientists to..." expresses the result or direction of the action. The infinitive "to isolate" is the correct form to follow "leading scientists."