I think you should go back to your _____ plan, which is much more practical than the present one.

A．random

B．original

C．abstract

D．ridiculous

某同学从一块大岩石上砸下一小块岩石，用天平称得质量是27g，放入装有80mL水的量筒中，水升至90 mL，这块岩石的密度是________ Kg/m³，大小两块岩石的密度是_____（填“相等”或“不相等”） 。