6
Answer: ASet 6: Words in Context (Intermediate)
Explanation
PASSAGE
The mechanism by which the drug works remains _____ understood by researchers.
Which choice completes the text with the most logical and precise word or phrase?
A. poorly✓ Correct
B. completely
C. easily
D. perfectly
Detailed Answer Explanation
Choice A is the best answer. "Poorly" is correct because it means "in a way that is not satisfactory." The context clues in the passage indicate that this meaning best completes the sentence logically.
Why others are wrong: B ("Completely" means "totally," which doesn't fit the context.), C ("Easily" means "without difficulty," which doesn't fit the context.), D ("Perfectly" means "in a complete manner," which doesn't fit the context.).