图书馆员的知识结构是指图书馆员自身（）或知识体系。
参考答案：知识素养
—Who's that woman standing near the library? Is it your English teacher Miss Green?
—It ______. be Miss Green. She has gone abroad. [ ]
A. must
B. can't
C. may
D. shouldn't
为了判断胎儿成熟度，应测孕妇的（）
A.尿中孕二醇值
B.尿中雌三醇值
C.血中甲胎蛋白值
D.羊水中肌酐值
E.羊水中人胎盘生乳素值
