單格填空第 19 題
There may be a threshold below which blood pressure reductions become ______ given that a long-running study showed no decreased heart risk for drops in blood pressure below a certain point.
| Blank |
|---|
| (A) worthwhile |
| (B) indiscernible |
| (C) arduous |
| (D) significant |
| (E) superfluous |
出處：OG, p.513, #4