Not all objects can be differentiated based on shape. Neither do all objects with the same shape have similar functions. Objects can also be segregated on the basis of colour, function, size, density, etc. 

Belts, purse, and jacket - all of these are made of leather.

A Computer is made of different materials like plastic, glass and metal etc. Whereas the other options like iron rods and tyres  and bottle are each made of the same substances individually. 

-Liquids do not have definite shapes; they take the shape of the container they are stored in. 
-They have definite volume.
-The particles of liquids are loosely packed compared to particles in solids
-They can be compressed to a small extent. 

The materials through which light cannot pass are called opaque. When light falls on an opaque object, some part of the light gets absorbed and the other part gets reflected back.

Materials which are difficult to compress are called hard materials.
Iron is the hardest material among all followed by wood and then paper.

Kerosene forms a layer above water when both the liquids are mixed and left to settle for some time. This is because the density of kerosene is less than that of water and they do not mix. 

Opaque objects do not allow the light to pass through them. 
Example:- Wood, Gold, etc.
Tranparent objects allow the light to pass through them while translucent objects partially allow the light to pass through them.

The density of corn syrup, vegetable oil and water is in the order:
Corn syrup > Water > Vegetable Oil.
The less dense material will float on top of the more dense material. 
Thus, vegetable oil will be the uppermost layer followed by water in the middle and corn syrup being at the bottom layer.