________knowledge is related to those non-professional vocations in which the majority of people work for most of their adult life.
句意：实用的知识与非专业性的职业相关，大多数人在他们的多数成年生活里都从事这样的职业。 utilitarian 功利性的。 functional 功能的。 comprehensive 综合的。 promotional 促销的。因此选 C。