单选题 The middle class mainly refers to people ______ .

【正确答案】 D
【答案解析】细节题。选项D意为“那些比较富裕的生意人或专业人士”。第一段的倒数第二句说:“The middle class consists chiefly of well-to-do businessmen and professional people of all kinds.”(中产阶级主要包括富裕的生意人和各种职业的人。)