Even more, the 'bilingual advantage hypothesis' is being challenged once again.

更重要的是，“双语优势假说”再次受到挑战。

They countered that no negative effects of bilingual education have been found.

他们反驳说，还未曾发现双语教育有负面影响。

Researchers now claim that earlier research on bilingual education was seriously flawed.

研究人员现声称，双语教育的早期研究存在严重缺陷。

In recent years, scientists have begun to show that the advantages of bilingualism are even more important than being able to converse with a wider range of people.

近年来，科学家开始表明双语的优势比与更多人进行交流更为重要。

'In the last 20 years or so, there's been a virtual explosion of research on bilingualism,' says Judith Kroll, a professor at the University of California, Riverside.

加州大学河滨分校的教授朱迪思·克罗尔表示：“在过去20年左右的时间里，对双语的研究实际上出现了爆炸式增长。”

It relates to the essential problem of bilingualism.

这与使用双语的一些基本问题有关。

What is bilingualism and diglossia?

什么是双语现象和双语体？

What's the difference between diglossia and bilingualism?

双语和双言现象有什么区别？