我国高等级公路边坡防护的研究起步较晚，至今仍处于不断完善和改进当中。

Our study of highway slope protection start late and still is constantly refining and improving.

youdao

我国高等级公路边坡防护的研究起步较晚，至今仍处于不断完善和改进当中。

Our study of highway slope protection start late and still is constantly refining and improving.

youdao