正常 * * 分泌物，不正确的是（）

A.呈酸性

B.球菌极少

C. * * 杆菌较多

D.白细胞较多

E.鳞状上皮细胞较多

My sister met him at Ningbo Grand Theatre yesterday afternoon, so he         your lecture.

A．couldn’t attend

B．mustn’t have attended

C．shouldn’t attend

D．couldn’t have attended