00298nam a2200109 a 450000500170000000800410001705000190005824500420007726000230011944000230014265000230016520140513081058.0100907s19uu    xx            00    eng d  aVCDbUp69 2008  aUps and downs:bfloating and sinking.  bScholastic,c2008.  aMagic School Bus :  agravity ; bouyancy