第2题: [单项选择]慢性主动脉瓣狭窄患者病程中,最晚出现的病理生理变化是 A. 左心房后负荷增加 B. 左心房代偿性肥大 C. 左心室压力负荷增加 D. 左心室舒张末容量增加 参考答案:D 答案解析:主动脉瓣狭窄时→左心室压力负荷增加→左心室肥厚→左心室顺应性降低→左心室舒张压增高→左心房后负荷增加→左心房肥大→左心室充盈增加→左心室舒张末容量增加。可见,左心室舒张末容量增加直至病程晚期才出现。
A. Managers. B. Businessmen. C. Professors. D. Politicians. 参考答案:D 答案解析:[命题目的] 本题考查对文章细节的理解。 [解题要点] 根据题意,确定答案在文章最后一句话“...this debate is primarily in political circles...
A. Call on people to protect sharks. B. Point out the living environment of sharks. C. Explain why the sharks are dangerous. D. An introduction to sharks. 参考答案:D 答案解析:[听力原文]17-20 Scientists say sharks have lived in the world's oceans for millions of years. Sci