Solution:
Neurons (also called neurones or nerve cells) are the fundamental units of the brain and nervous system, the cells responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in between.

Solution:
None of the above

Solution:
To prevent damage from lightning, lightning conductors are used on tall structures. The lightning conductor should be made of a good conductor like copper with sharp-pointed edges.

Solution:
Simple microscope - light microscope consisting of a short focus single convex lens is used to produce an enlarged image. The magnifying glass was invented by Roger Bacon in 1250. In the original ‘simple’ microscopes, a single light path went through the object viewed and one lens, increasing the visibility of the object by some amount (magnification). (One light path, one lens = simple microscope) Compound refers to the fact that in order to enlarge an image; a single light path passes through a series of lenses in a line. Each lens magnifies the image over the previous one. (One light path, multiple lenses = compound microscope) Usually, a modern compound microscope has multiple lenses within the eye tube, and a series of three or four objective lenses on the ‘head’ which can be rotated into place. The image produced is a two dimensional (2-D) image.

Solution:
Simple machine make work easier and work input > work output.

Solution:
8 bottles of water makes a gallon.

Solution:
The cassette tape contains a magnetic strip wound around two spools. Tiny magnetic particles are randomly scattered throughout the tape. A tape recorder should not be kept near a magnet as the latter can cause the magnetic material to be pushed and pulled out of place. Rearranging the magnetic particles erases the sound.