然而各种华语作为第二语言教材缺乏明确统一的水平等级标准作为编写参考。

However, there is a lack of a uniform compilation standard for such teaching materials.

youdao

然而各种华语作为第二语言教材缺乏明确统一的水平等级标准作为编写参考。

However, there is a lack of a uniform compilation standard for such teaching materials.

youdao