Select the correct answer.
Which substance is made of polymers?
A.
marble
B. protein
OC.
salt
D. steel

B) protein

Explanation:

A polymer is defined as a molecule which has 'n' number of monomer units.

For example, (CH_{2}=CH_{2})_{n} is a poly ethene polymer.

Similarly, proteins are also polymers as they are made up of amino acids and contain number of repeated units just like polymers.

Thus, we can conclude that protein is made of polymers.

a police officer and a ambulance

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.