对SPA叙述正确的是
A.是葡萄球菌表面蛋白
B.与协同凝集试验有关
C.所有葡萄球菌都有
D.具有抗吞噬作用
E.能与人IgG的Fc段发生非特异性结合
参考答案:A, B, D, E
He has poor eyesight _______computer work.[ ]
A. because too many
B. because too many
C. because of too much
D. because of much too
刷牙是预防牙周疾病的好方法,下面哪种提法更好些
A.正确刷牙
B.早晚刷牙
C.认真刷牙
D.有效刷牙
E.饭后刷牙