Scientists didn’t know much about lung cancer _____.

Scientists didn’t know much about lung cancer _____.
A、before long
B、long before
C、until recently
D、very soon
【正确答案】：C
【题目解析】：before long 没过多久；long before 很久之前；until recently 直到最近；very soon 句意：直到最近科学家们才对肺癌有了更多的了解，因此C符合题意