问题
单项选择题
In a sample of associates at a law firm, 30 percent are second-year associates, and 60 percent are not first-year associates. What percentage of the associates at the law firm have been there for more than two years ？（）
A. 10
B. 20
C. 30
D. 40
E. 50
答案
参考答案：C
解析：
The answer must be a subset of the 60 percent of associates that are not first-year associates. Of these, you must subtract the 30 percent that are second-year associates, leaving only 30 percent, so the answer is C.