A. its empire fell to pieces B. its soil became hard and poor C. it cut too many trees down D. without its trees, it could not get any fruit to eat 参考答案:C 答案解析:此题中C最符合题意。由于大量采伐树木，生态植被遭破坏，人类不可避免的将受到大自然的惩罚。
第13题: [单项选择]The message "all drugs are terrible for you" is not influential because ______ A. it ignores the fact that drugs vary greatly in danger B. it gives a false account of the risks of drag use C. some drugs are good for health D. it does not appear in underground papers 参考答案:A 答案解析:根据原文中第一段第三句和第四句"Such sources are influential，because they do not give a simple' all drugs are terrib
第20题: [单项选择]小便频数，色红、量少、灼痛，伴腰痛者多见于 A. 腰膝酸软，神疲乏力，耳鸣失聪，小便频数而清 B. 腰膝酸软而痛，眩晕耳鸣，齿松发脱，五心烦热，潮热盗汗 C. 成人早衰，耳鸣耳聋，健忘恍惚，两足痿软，发脱齿摇 D. 身体浮肿，腰以下尤甚，按之没指，畏寒肢冷，腰膝酸冷 E. 面色白或黧黑，腰膝酸冷，形寒肢冷，下肢为甚，神疲乏力 参考答案:A
