（ ） is a phenomenon that in some speech communities two languages exist side by side with each having a different role to play, and language switching occurs when the situation changes.
A.Bilingualism B.Diglossia C.Pidgin D.Creole正确答案A
（ ） is a phenomenon that in some speech communities two languages exist side by side with each having a different role to play, and language switching occurs when the situation changes.
A.Bilingualism B.Diglossia C.Pidgin D.Creole正确答案A
