中 * * 党是工人阶级的先锋队是从()和()概括党的性质。
参考答案:阶级性;先进性
在人血清中含量最多的IgG亚类是()
A.IgG1
B.IgG2
C.IgG3
D.IgG4
E.IgG1、IgG2
Scarecely had the van turned the corner than the mirror came off.()
A. No more
B. No sooner
C. Not any
D. No longer