Answer:
Methane is a chemical compound with the chemical formula CH4, symbolizing one atom of carbon and four atoms of hydrogen. It is a group 14 hydride and the simplest alkaline, and is the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure. Methane naturally occurs both below ground and under the seafloor, and is formed by both geological and biological processes. In nature, methane is produced by the anaerobic bacterial decomposition of vegetable matter under water. Methane is important because it can be captured from landfills, can be burned to produce electricity, heat buildings, or power garbage trucks. Methane can also be captured from farm digesters, which are big tanks that contain manure and other waste from barns that house livestock such as cows and pigs. In fact, Jordan Dairy Farms in Massachusetts uses a biodigester to turn cow manure into methane gas, which is used for fuel or turned into electricity.
Dysentery is caused as a result of bacterial infection caused by an unusual strain of E.coli. The E.coli is found normally in the intestine but during infection watery diarrhea along with mucous and blood is there.
Dysentery can also be caused by other infectious pathogens such as bacteria, parasites or viruses. The infection is caused when the pathogen enters the large intestine via mouth due to consumption of contaminated water or food, oral contact with the objects which are contaminated.
The treatment to the infection is through antibiotic drug.
Group 7A, the Halogens contain metalloids such as Astatine.
Answer:
I believe c not completely sur e though
Explanation:

Last option: Preserve an ecosystem

• The establishment of a bird reservation is a way to preserve an ecosystem because reservation provides suitable environment to organism. A healthy ecosystem means large number of biodiversity.