第10题: [单项选择]如果颈内动脉阻塞或高度狭窄,同侧颈总动脉将出现哪种变化()。 A. 阻力指数降低 B. 阻力指数升高 C. 收缩期峰值流速降低 D. 舒张期峰值流速升高 E. 血流反向 参考答案:B 答案解析:颈内动脉狭窄,造成颈总动脉前方血流阻力增加,收缩期峰值流速相对增快,舒张期流速减低,根据阻力指数公式RI=(收缩期峰值流速-舒张末期流速)/收缩期峰值流速,因此阻力指数升高。
第16题: [单项选择]{{B}}Questions 11 to 18 are based on the conversation you have just heard.{{/B}} A. The unsmiling faces. B. The sun. C. The residents. D. The weather. 参考答案:D 答案解析:[听力原文]
M:You have been in London for several months.How do you like the city
W:The only thing is