Sab saum toj riam thiab hauv qab riam thov
Oct 11, 2018
Qhov ob hnub so ntau saum riam thiab hauv qab riam thov, yog li ntawd peb yuav teb koj lig me ntsis. Lub lim tiam tom ntej no, yuav nce siab. Sib tham ntawm no, leej twg xav tau riam ncig, thov sau tias cov ntaub ntawv Suav rau saum riam thiab hauv qab riam yog 9CrSi, Cr12MoV thiab GCr15.