However , it has been found that even people insensitive to a certain smell at first can suddenly become sensitive to it when exposed to it often enough . (05,完型)

【重点词汇解析】insensitive，adj. 感觉迟钝的；expose，vt. 使曝光、揭露、显示

【参考翻译】然而我们却发现，即使某些人开始时对某种气味不敏感，如果经常接触这种气味，也会对它敏感起来。