A.堅(jiān)硬巖石B.半堅(jiān)硬巖石C.軟弱巖石D.極軟弱巖石
A.極堅(jiān)硬巖石B.半堅(jiān)硬巖石C.軟弱巖石D.極軟弱巖石
A.5cm x 5cm x 5cmB.7cm x 7cm x 7cmC.10cm x 10cm x 10cmD.15cm x 15cm x 15cm