Cov khoom

Lus piav qhia luv luv:

Hlau kaum daim kab xev yog ua los ntawm siab tensile lub zog daim ntawv sib koom daim kab xev raws li cov ntaub ntawv thaub qab, ntxiv dag zog los ntawm ob qho tib si los tiv thaiv xeb hlau strips.Nws yog siv los tiv thaiv phab ntsa kaum ntawm qhov cuam tshuam, tshwj xeeb tshaj yog qhov zoo tshaj plaws rau qhov tsis xwm yeem sab hauv thiab sab nraud, uas yog hloov tau rau cov ces kaum ntawm phab ntsa nrog cov ces kaum tsis nyob ntawm 90 degree.