3. Narrowing your criteria, for example, may work against you:"Every time you answer a question you eliminate a possibility,"says one expert.

【分析】句子主干为Narrowing your criteria ... may work against you。for example为插入语；冒号后面的成分是对前面句子的解释说明。

【译文】例如，缩小搜索条件可能对求职者产生不利影响。一个专家说，“你每回答一个问题，就失去了一个做另外一种工作的机会”。

4. For any job search, you should start with a narrow concept-what you think you want to do-then broaden it.

【分析】句子主干为 you should start with a narrow concept...then broaden it,其中包含两个并列的谓语动词 start with 和 broaden;介词短语 for any job search 为状语；破折号之间的部分是对concept的解释说明。

【译文】找任何工作时，你都应该从一个狭窄的范围开始——你认为你想干的工作——然后拓宽它。