以下对于隐私的理解正确的是　　[ ]

A．不愿为人所知的事情　　　

B．与公共利益、群体利益无关，而不愿为人所知的纯个人私事　　　

C．与个人有关的事情　　　

D．个人不愿为人所知、侵扰的秘密　 

Since the end of World War Ⅱ, teachers have found themselves under considerable pressure to abandon the long-standing ______ model, though it had been in general use in second language teaching since the late 18th century.