First of all, we need to make a half hollow ice cube, which is a mold. Ice becomes ice.

Then, melt it a little, take out the ice, and put two and a half pieces in another ice mold.

Two pieces are half combined into one piece, and then quickly frozen. It becomes a complete hollow ice cube.

Several advantages of hollow ice over solid ice: 1, fast cooling of drinks; Liquefaction principle of ice cubes with the same volume and different mass.

2, the floatability is improved; It won't block the straw, but the sinking of ice will block the straw. 3. Weak dilution; After the solid ice melted, the drink was too weak. 4. Avoid waste; Solid ice melts too slowly.