第27题: [单项选择]双下吱对称性紫癜伴荨麻疹者常见于()。 A. 过敏性紫癜 B. 再生障碍性贫血 C. 激素性紫癜 D. 血小板减少 E. 特发性血小板增多症 参考答案:A 答案解析:过敏性紫癜是因机体对某些致敏物质发生变态反应,导致毛细血管脆性和通透性增加,常表现为双下肢对称性紫癜,并可同时出现皮肤水肿、荨麻疹等其他变态反应表现。B、C、D、E等虽亦可引起双下肢对称性紫癜,但多无
第30题: [单项选择]What does the passage mainly discuss A. Disagreements on the meaning of folk music. B. Elements that define folk music. C. Differences between folk music and popular music. D. Themes commonly found in folk music. 参考答案:B 答案解析:[分析] 主旨题。B选项是最佳答案,短文主要讲的是界定民间音乐的要素。虽然短文开头提到:...there is still a good deal of disagreement as to what