Diatoms contain in their cell walls. This material is used industrially in the production of toothpastes, silver polishes, and swimming pool filters.

silica

Explanation:

Diatoms are microscopic organisms.  they have  shell that is made from organic compounds and silica.Diatoms contain silica in their cell walls. This material is used industrially in the production of toothpastes, silver polishes, and swimming pool filters. Silica is used to remove  stains and debris.

supercell thunderstorms are perhaps the most violent of all thunderstorm types, and are capable of producing damaging winds, large hail, and weak-to-violent tornadoes

c is the answer to this question. altitude affects the weather because air molecules evaporate.