Kev ua raws li ASTM tus qauv:
Txhawm rau xyuas kom cov khoom lag luam ruaj khov
Lub chaw soj nstuam yog tag nrho nrog cov khoom siv kuaj uasstrict ASTM cov qauv ntsuas yog siv.
Kev xeem zoo
● Txawm tias kim, tsis muaj ib qho khoom siv pov tseg rov qab siv dua.|● Txawm tias nyuaj, tsis muaj ib feeb xoob rau kev tswj kom zoo.