第6题: [单项选择]可引起第一心音增强的是（） A. 主动脉瓣狭窄 B. 二尖瓣关闭不全 C. 主动脉瓣关闭不全 D. 二尖瓣狭窄 E. 左心功能不全 参考答案:D 答案解析:第一心音强度与心肌收缩力、心室充盈度、瓣膜的弹性及瓣膜关闭前所处的位置有关，心肌收缩力强、心室充盈度小、瓣膜关闭前所处位置低且弹性好时，第一心音增强，反之则减弱。
第11题: [单项选择]If you are writing or studying, it makes very much difference where the light comes from. People who use books and pens every day (41) to be especially careful about the direction from which the light shines on their work.[A] eyes [B] face [C] baek 参考答案:A 答案解析:考查名词与上下文理解。eye眼睛；face脸；back背(部)。由上下文与常识可知，脸朝窗户时，光线会照着眼睛、影响阅读，故选[A]。
第18题: [填空题]He doesn’t seem to ______ (意识到他们态度的冷淡) towards his appeal. 参考答案:be aware of the coldness of their attitude 答案解析:[考点] 固定搭配【考频：35】。 [精析] “意识到”可译成be aware of或be conscious of；“态度的冷淡”可译成the coldness of their attitu
A. One hour. B. Two hours. C. One and half. D. Two and hal 参考答案:D 答案解析:根据报道，研究结果建议人们每周进行两个半小时(即150分钟)的体育锻炼：follow the widely recommended approach of at least 150 minutes o
