What was one of the main reasons for the change in architectural style in eighteenth century North America a. More architects arrived in the colonies. b. The colonists developed an interest in classical architecture. c. Bricks were more readily available. d. The colonists had more money to spend on housing.
参考答案：D
解析：[听力原文]Seventeenth-century houses in colonial North America were simple structures that were primarily functional, carrying over traditional designs that went back to the Middle Ages. During the first half of the eighteenth century, however, houses began to show a new elegance. As wealth increased, more and more colonists built fine houses.
[分析]： 因果关系的判断。 根据原文有关18世纪北美殖民地建筑风格改变的描述是“As wealth in creased, more and more colonists built fine houses.”由此可见财富的增长是其原因。因此，选项d的说法是正确的。[解题关键] 掌握表因果关系的信号词，有助于迅速在原文定位信息点，并作出正确的因果关系判断，该文中使用了信号词as。