健康大课堂属于（）
A.营养宣教演讲
B.学术演讲
C.健康演讲
D.礼仪演讲
参考答案：C
The magician picked out several persons ______ from the audience and asked them to help him with the performance.
A．by accident
B．on average
C．on occasion
D．at random
可引起亚急性细菌性心内膜炎的病原体是（）
A．艰难梭菌
B．苍白密螺旋体
C．甲型溶血性链球菌
D．白假丝酵母菌(白念珠菌)
E．变异链球菌
