To study this property, a long-term test method has been used for many years.

为了研究这种性能，许多年来一直采用传统的长期试验方法。

youdao

To study this property, a long-term test method has been used for many years.

为了研究这种性能，许多年来一直采用传统的长期试验方法。

youdao