试题题干
The world has about 3000 languages, which can be grouped into roughly 300 language families on the basis of similarities in their basic word stock and（）.
参考答案
正确答案：
试题解析
据估计，世界上约有3000多种语言。这些语言可以根据它们的基本词汇和语法的相似性大致划为300个谱系。