解释: 1. 此题关键在于对句子结构的划分以及对search用法的理解。 2. 句子主语是Many of the new metropolitan residents,后面是系表结构were business and professional people,所以后面的成分为后置定语,修饰表语business and professional people. 3. 而答案D是一个句子的谓语结构,它不能做后置定语,排除D。 4. search的直接宾语是指“搜索/搜寻的范围/场所”,search for的宾语才是指“搜寻的目标”,所以如果要用现在分词短语(被修饰词business and professional people和动词search for直接为主动关系,必须用其现在分词形式)做后置定语,必须是searching for higher incomes than they could earn in the small towns and rural South. 所以,BC(怎么是一样的?)错误。 5. in search of...是一个介宾短语(其中的search为名词),它在句中可以充当状语/后置定语/表语/补足语等。