第20题: [单项选择]大部分急性心肌梗死的病因是() A. 冠状动脉内动脉粥样斑块破裂,血栓形成 B. 冠状动脉痉挛,血栓形成 C. 动脉粥样斑块逐渐进展直至完全阻塞冠状动脉管腔 D. 冠状动脉炎,血栓形成 E. 冠状动脉栓塞,继发血栓形成 参考答案:A
第21题: [单项选择]What he said just now had little to do with the question ______ discussion. A. on B. in C. under D. at 参考答案:C 答案解析:本题考查介词搭配。“在……的过程中,正在经受”用介词under,根据句意,只有选项C与题意相符。常见的类似搭配还有:under construction“正在建设中”,under repair“正在修
第23题: [单项选择]When we were in the mountains, we often found ourselves entirely enveloped by the fog. A. confined B. surrounded C. darkened D. blocked 参考答案:B 答案解析:[解析] 本题中,envelope意为“包住,笼罩”。四个选项中,surround意为“包围,环绕”,如:The fence surrounds the school.(篱笆环绕着学校。)confin