B) a smokestack for an electric power plant
300km is closest to maximum tickness of a plate.
<span>First, he should inform all the people who might be in the building to quit immediately.
Since the content which was in the pipette is not known they vacate and let the investigation to be carried out.
If the content is known, then the procedure on how to lean up the mess is carried out. After that people can go back to their normal duties.</span>
Answer:
Nucleus
the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
Nucleolus
a small dense spherical structure in the nucleus of a cell during interphase.