A. were not able to help laughter B. could not help but laughing C. could not help laughing D. could not help to laugh 参考答案:C 答案解析:情态动词。can't/couldn't help doing sth.意为“忍不住做某事”。
第36题: [单项选择]男性,28岁,腰背及膝髋部痛一年,晨活动发僵,时而双眼红痛;体检:骶髂关节处压叩痛,X线无异常, ESR 28mm/h。为确诊进一步应查 A. 双膝关节X线片 B. PPD试验 C. 血HLA-B27 D. 血抗核抗体 E. IgM型RF 参考答案:C 答案解析: 根据此病人腰背及膝髋部痛伴晨僵,还有关节外表现,即双眼红痛(可能是结膜炎),这些都支持强直性脊柱炎的诊断,而不支持类风湿关节炎。强直性脊柱炎无特异性或标记性实验室指标,而HLA-B2
第38题: [单项选择]测定SO2的质量分数,得到下列数据(%):28.62,28.59,28.51,28.52,28.61;则置信度为95%时平均值的置信区间为( )。(已知置信度为95%,n=5,t=2.776) A. 28.56±0.12 B. 28.57±0.13 C. 28.56±0.13 D. 28.57±0.12 参考答案:D