Cov kev qhia tshwj xeeb ntawm ob kab rau cov menyuam chains feem ntau suav nrog cov qauv saw, tus lej ntawm kev sib txuas, tus naj npawb ntawm cov menyuam, thiab lwm yam. 1. Cov qauv ntawm cov hlua khi: Cov qauv ntawm ob kab rau cov menyuam saw feem ntau muaj cov lej thiab cov ntawv, xws li 40-2, 50. -2, thiab lwm yam. Ntawm lawv, tus lej sawv cev rau lub log ntawm cov saw, ...
Nyeem ntxiv