标题: GWD-13-Q13 求关于冠词用法的解答 [打印本页] 作者: hanlei8492 时间: 2010-9-29 17:06 标题: GWD-13-Q13 求关于冠词用法的解答 Being that she was secretary of labor, Frances Perkins' considerable influence with Franklin D.Roosevelt was used preventing him from restraining strikes by longshoremen and automobile workers. 正确答案是C. As secretary of labor, Frances Perkins used her considerable influence with Franklin D.Roosevelt to prevent 这个答案的选择没有问题，但是我的问题在于： Secretary是可数名词，为什么不是As a secretary？什么时候可以省略a?