Jack, who pretended       , heard, however, every word that was said.

A．not listening

B．not to be listened

C．not to be listening

D．not having listened

鉴于近年来痢疾杆菌的耐药菌株日益增多，故在应用抗生素时应考虑选用以下哪种

A．氨苄青霉素

B．庆大霉素

C．磺胺甲基异嘿唑

D．头孢噻肟钠或头孢三嗪

E．阿奇霉素