Many married couples always wonder how to keep their ______ happy in<br/>the marriage. A: species B: defiance C: spouses D: binders

Expendable molds , which typically are made of sand, plaster, ceramics, and similar materials and generally are mixed with various binders(bonding agents) for improved properties. These materials are refractories (that is, they are capable of with standing the high temperatures of molten metals). After the casting has solidified, the mold is broken up to remove the casting.