The thins brought down by rivers from the mountains that are useful for cultivation are______.
A. deltas
B. crops
C. fresh water life
D. soil and minerals
正确答案：D
55．答案为D此题为细节题文章中的第六段第一句：Riversalsobringdownsoilandmineralsfromthemountains说明了河流从山上带来的是；土壤和矿物质答案为D
