细菌具有抗吞噬作用的表面结构是（）
A.菌毛
B.荚膜
C.细胞膜
D.多层肽聚糖
E.芽胞
参考答案：B
He will have learned English for eight years by the time he ______ from the university next year.[ ]
A. will graduate
B. will have graduated
C. graduates
D. is to graduate
宫腔变形的妇女是不可以使用宫内节育器的。
