Questions

From the given conditions ,

only A = 27 yrs satisfies.

A DVD is an example of Optical Disc.

The branch of biology that studies the different structures and functions of the cell is called Cell Biology or Cytology.

 A cell is the smallest unit of life that can replicate independently, and cells are often called the "building blocks of life"

Cell Biology deals with :

• Life cycle 

• Structure and organisation of cell organelles and their physiological properties. 

• Metabolic processes 

• Interactions with their environment 

• Signalling pathways.

Waterloo

Doing more work in less time, results in an increase in power to do a work.

Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity.

Because the electrons in the atom's higher energy levels can separate from the atoms easily, they can be pulled out with very little energy. Because the molecular structure of the metal is such that 'free electrons' are free to move, thus being categorized as electrically conductive.

For example, copper is used for electrical wiring because it is a good conductor of electricity.

The two concepts that explain how the body moves are force and balance.