Questions

Tuberculosis (TB) is caused by a type of bacterium called Mycobacterium tuberculosis.

It's spread when a person with active TB disease in their lungs coughs or sneezes and someone else inhales the expelled droplets, which contain TB bacteria.

One would have to spend prolonged periods (several hours) in close contact with an infected person to catch the infection yourself.For example, TB infections usually spread between family members who live in the same house. It would be highly unlikely for you to become infected by sitting next to an infected person on a bus or train. Hence, statement 1 is incorrect.

It is Charcoal which is black when we buy it or when not being used. It gets red in appearance when put in use means to say when burning. And eventually when it's been consumed by fire or after getting burned out or used up, changes into ashes which look grey in color.