【题目】This medicine is quite beneficial to your recovery after the operation, ________ you take it as told.
A.unless
B.providing
C.considering
D.since

【答案】B
【解析】考查状语从句。句意：这种药只要你按要求服用肯定有益于你手术后的恢复的。“providing…”可以用来引导条件状语从句表示“只要…”，符合语境，故B项正确。