第13题: [单项选择]An analyst does research about covariance. If the standard deviation of returns of an asset is 0.8367%, the covariance of the asset's returns with themselves (in unit of percent squared) is closest to:() A. 0.70 B. 0.91 C. 1.00 参考答案:A 答案解析:
第29题: [单项选择]患者,女性,34岁,无明显诱因出现左下腹部疼痛,伴恶心呕吐。无停经史。查体:急症面容,脸色苍白,血压110/70mmHg,下腹有压痛和反跳痛,移动性浊音(-),体温38.5℃,血HCG正常,血白细胞升高。经阴道超声检查,于左下腹见50mm×55mm类圆形囊性为主的混合性肿块,边界尚清晰.被膜较厚,一侧囊肿壁旁可见高回声光团伴声影,囊性部分内有密集细小点状回声飘动,被膜周围可见细小低回声暗带,请问该患者最可能患的疾病是()。 A. 肠炎 B. 阑尾炎 C. 卵巢囊肿蒂扭转 D. 宫外孕 E. 卵巢囊性畸胎瘤蒂扭转 参考答案:E