关于免疫球蛋白，下列描述错误的是（） A.是具有抗体活性的球蛋白 B.由浆细胞产生 发布时间：2017-05-05 17:30 │ 来源：www.tikuol.com 题型：单项选择题 A1/A2型题 问题： 关于免疫球蛋白，下列描述错误的是（）A.是具有抗体活性的球蛋白B.由浆细胞产生C.存在于血液、体液及外分泌液中D.不存在于细胞膜上E.有特异性识别抗原的功能
题型：单项选择题 A1/A2型题 为五聚体结构，在免疫球蛋白中分子量最大；在感染和疫苗接种以后，最早出现的抗体，新生儿的脐血中如发现升高，提示有宫内感染，这是以下哪一种免疫球蛋白的特点（）。A.IgAB.IgGC.IgMD.IgDE.IgE 查看答案
题型：单项选择题 A1/A2型题 Reading comprehension. The following card includes a brief summary and a short assessment of a research paper. It can provide a guide for further reading on the topic. Trevor, C. O., Lansford, B. and Black, J. W., 2004, "Employee turnover (人事变更) and job performance: monitoring the influences of salary growth and promotion", Journal of Armchair Psychology, vol. 113, no.1, pp. 56-64. In this article Trevor et al. review the influences of pay and job opportunities in respect of job performance, turnover rates and employees' job attitude. The authors use data gained through organizational surveys of blue-chip companies in Vancouver, Canada to try to identify the maincause of employee turnover and whether it is linked to salary growth. Their research focuses on assessing a range of pay structures such as pay for performance and organizational reward plans.The article is useful as Trevor et al. suggest that there are numerous reasons for employee turnoverand a variety of differences in employees' job attitude and performance. The main limitation of thearticle is that the survey sample was restricted to mid-level management, thus the authors indicate that further, more extensive research needs to be undertaken to develop a more in-depth understanding of employee turnover and job performance. As this article was published in a professional journal, the findings can be considered reliable. It will be useful additional informationfor the research on pay structures. 1. The research paper published is primarily concerned with _____.[ ]A. the way of preventing employee turnover B. methods of improving employee performance C. factors affecting employee turnover and performance D. pay structures based on employee performance 2. As is mentioned in the card, the limitation of the research paper mainly lies in that _____. [ ]A. the data analysis is hardly reliable B. the research sample is not wide enough C. the findings are of no practical value D. the research method is out-of-date 3. Who might be most interested in this piece of information? [ ]A. Job hunters. B. Employees in blue-chip companies. C. Mid-level managers. D. Researchers on employee turnover. 查看答案