MAT 110 · Materials TestingSession 4 · Hour 1 · HardnessInstructor cue 숫자 있는 자국.90 minNow Open · 5 min left · next Demo한ENScriptBodyClearHour 1HardnessHour 2Follow HardnessHour 3Your turn · HardnessHour 4Check HardnessThis browser cannot play the film.CheckA dent with a number. Week 4: name, order, result. Then A dent with a number.