Lub qhov rooj hluav taws kub yog ua los ntawm cov hluav taws kub-resistant ntoo los yog cov khoom siv hluav taws kub-resistant xws li lub qhov rooj thav duab, lub qhov rooj ntawm lub qhov rooj, thiab lub qhov rooj nplooj ntoo. . Lub sijhawm tiv thaiv hluav taws ntawm lub qhov rooj ntoo yog muab faib ua: Chav A yog 1.2h, Chav B yog 0.9h, thiab Chav C yog 0.6h. Txais tos kom sab laj peb.