0.5m3的冰块完全融化为水后,体积变为0.45m3,则冰块的质量是_________kg,冰块的密度是___________g/cm3.
450; 0.9 .
下表所列各组物质中,物质之间通过一步反应就能实现如图所示转化的是
A.①②③④
B.①②③
C.①③④
D.②④
Yesterday was my birthday. My friend sent me a CD is made by Han Geng.
A.who
B.what
C.which
D.whom