第18题: [单项选择]Oceanographers are concerned because A. their knowledge of this phenomenon is limited. B. they believe the oceans are dying. C. they fear an invasion from outer space. D. they have identified thousands of alien webs. 参考答案:A 答案解析:海洋学家担忧的主要原因是:“What concerns Carlton and his fellow marine ecologists is the lack of knowledge about
第20题: [单项选择]男性,30岁,突发性左上腹部绞痛5小时,不发热,血象正常。尿常规:红细胞20~30个。超声检查:左肾集合系统轻度分离,同侧输尿管上段约0.5cm,其远侧段显示不清。该病例可能是()。 A. 肾细胞癌 B. 急性肾盂肾炎 C. 急性肾小球肾炎 D. 输尿管结石 E. 肾血管平滑肌脂肪瘤 参考答案:D 答案解析:患者的超声检查所见结合典型的临床症状和化验检查,输尿管结石可能性大。