A.Flinders bar first,then the heeling magnet and spheres
B.Heeling magnet first,then the Flinders bar and spheres
C.Flinders bar first,then the spheres and heeling magnet
D.Spheres first,then the Flinders bar and heeling magnet
A.Switch
B.To switch
C.Switched
D.Will switch
A.My using
B.I use
C.To use
D.I will use