TOEFL Reading: ETS-TOEFL阅读机经 - 67O50D1P73J98Z2AL$

All of the following are mentioned in paragraph 2 as changes over time in the pattern of wood use in prehistoric settlements EXCEPT: A. Cottonwood was increasingly used in hearths. B. Fewer pinon trees were used in building construction. C. Juniper wood was increasingly used in hearths. D. The pinon wood used in construction came increasingly from older trees.