问题
单项选择题
________a language family is a group of languages with a common origin and similar vocabulary, grammar, and sound system.
A．What linguists call
B．It is called by linguists
C．Linguists call it
D．What do linguists call
答案
参考答案：A
解析：语法应用。本句是用名词性从句What do linguists call a language family作主语；意思是语言学家将一组有着共同起源，类似词汇、语法及音系的语言称为语系。