000 00285nam a22001217a 4500
040 _ads
245 _aKids Discover -- 2013 -- March
650 _aSimple machines.
_92903
650 _aLevers.
_92904
650 _aInclined plane.
_92905
650 _aPulley.
_92906
942 _2ddc
_cJ PER
999 _c50583
_d50583