History is one of the basic disciplines in middle schools. It is the necessary component of knowledge structure of the students.

中学历史学科是基础教育学科之一，是中学生知识结构、学力结构的必要组成部分。

youdao

To protect the eyes, it is necessary and essential to understand the basic knowledge of eyelid diseases.

如要保护眼睛，眼皮疾病的基本的知识是必要与必须的。

youdao

The basic knowledge of 3d CAD which was necessary to the simulation was briefly interpreted.

对模拟所必须具备的三维CAD知识进行了简要解说。

youdao

While impressive this will only chip away at the inequities that exist worldwide where the poor are not provided with the basic knowledge necessary to find a path to success.

FORBES: On the Wealth Gap and Entrepreneurship