根據(jù)甲乙兩圖所示,可推測出該金屬塊的密度為()
A.4.8g/cm3 B.4.88g/cm3
如圖所示,停表的讀數(shù)是()
A.5min37.5s B.5min7.5s C.6min7.5s D.6min37.5s
從圖可以看出()是界面,()是入射光線,()是反射光線,()是折射光線,入射角是()度,折射角是()度。()
A.CD;FO;OE;OG;60°;40° B.AB;GO;OE;OF;50°;30° C.AB;OE;OG;OF;30°;30° D.CD;FO;OE;OG;60°;50°