第4题: [单项选择]初种麻疹减毒活疫苗的时间是 A. 生后4个月 B. 生后2个月 C. 生后8个月 D. 4岁时加强1次 E. 8岁时加强1次 参考答案:C 答案解析:[解题思路] 麻疹初种年龄是生后8个月,此时由于从母体获得麻疹抗体已消失,应及时接种。
[命题规律] 考察“计划免疫”。必须掌握。
第24题: [填空题]Harvard President A. Lawrence Lowell has introduced the ______ system which offers undergraduates informal specialized instruction in their fields and now it is still a distinctive feature of Harvard education.
参考答案:tutorial 答案解析:[解析] 参见本文New Schools and New Houses部分第五段最后一句:The tutorial system,also introduced by Lowell and still