第11题: [单项选择]一艘轮船从河的上游甲港顺流到达下游的丙港,然后调头逆流向上到达中游的乙港,共用了12小时。已知这条轮船的顺流速度是逆流速度的2倍,水流速度是每小时2千米,从甲港到乙港相距18千米。则甲、丙两港间的距离为( ) A. 36千米 B. 48千米 C. 30千米 D. 44千米 参考答案:D 答案解析:[解析] 顺流速度-逆流速度=2×水流速度,又顺流速度=2×逆流速度,可知顺流速度=4×水流速度=8千米/时,逆流速度=2×水流速度=4千米/时。设甲、丙两港间距离为x千米,可列方程辨8+(x-18)
第12题: [单项选择]
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该患者首先需要排除的疾病是() A. 支气管内膜结核 B. 支气管肺癌 C. 渗出性胸膜炎 D. 支气管扩张 E. 慢性支气管炎 参考答案:A
第19题: [单项选择]Questions 19 to 22 are based on the conversation you have just heard. A. They defend the bone against viruses. B. They prevent oxygen from entering the bone. C. They connect the bone to muscle tissue. D. They break down bone tissue. 参考答案:D 答案解析:[听力原文] What is the function of the first group of specialized cells discussed in the talk