The light bulb was an innovation of

a. guglielmo marconi

b. thomas edison

c. alexander graham bell

d. jean lenoir

e. gustav eiffe

The light bulb was an innovation of B. Thomas Edison. Although it existed even before him, he is still credited for this patent because his was the best one there was at the time. He started working on the light bulb in 1878. 

The answer is as follows in the photo

Iassume the answer is 75 feet. inwards to outwards rather than outwards to inwards. probably be 75.hachures are stokes drawn in direction of the steepest slope. a series of short parallel lines drawn on a map to indicate topographic relief. it is actually called hachures on contour lines. the small marks in the center of the feature are called hachures.observe the picture attached