题型:问答题 简答题 The natural resources, such as mine, forest, and hydropower (水电) in that area have been ________. [ ]A. developed B. exploited C. improved D. expanded 查看答案
题型:问答题 简答题 风湿性心脏瓣膜病二尖瓣狭窄的特征性体征是()。A.心尖区舒张中晚期隆隆样杂音,递增型B.第一心音亢进C.肺动脉瓣区舒张早期吹风样杂音D.Graham-Steell杂音E.二尖瓣开放拍击音 查看答案