[单项选择]Passage 2 Questions 6 to 10 are based on the following passage. 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. Since architecture was not yet a specialized profession in the colonies, the design of buildings was left to carpenters who undertook to interpret architectural manuals imported from England. There are an astonishing number of these handbooks for builders in colonial libraries, and the houses erected during the eighteenth century show their influence. Most domestic architecture of the first three-quarters of the eighteenth century displayed a wide range of taste and freedom of application of the rules laid down in these books. Increasing wealth throughout the colonies resulte
A. the improved design of the 18th century colonial houses
B. the role of carpenters in building the 18th century houses
C. the varieties of decorations used in the 18th century houses
D. a comparison of the 18th century houses and modern houses