Regardless of the differences in the approximation of perfect bilingualism, most bilingual communities have one thing in common, that is, a fairly clear functional differentiation of the two languages in respect of speech situations known as ______.
A、diglossia
B、bilingualism
C、version
D、domains
【正确答案】：D
【题目解析】：Regardless of the differences in the approximation of perfect bilingualism, most bilingual communities have one thing in common, that is, a fairly clear functional differentiation of the two languages in respect of speech situations known as domains.