According to the natural terrain conditions, what are the two forms of landfill?

According to the natural terrain conditions, what are the two forms of landfill? ( )

A: Landfill and marine landfill.

Expansion: The harmless treatment methods of municipal solid waste widely used in the world mainly include landfill, incineration, composting, etc., and several technologies can also be effectively integrated for more systematic and comprehensive treatment. The United States put forward the concept of "sanitary landfill" in 1930s, and China implemented the most extensive garbage disposal technology-landfill.

There are 1748 sanitary landfills in China. The garbage disposal technology is to fill the garbage into a hollow pool or pit, and cover the part of the ground that contacts the garbage with impervious material to prevent the landfill leachate from entering the groundwater and causing pollution. And laying drainage pipes at the bottom of the site to lead the leachate to the outside; A gas guiding system is arranged in the garbage body to guide the utilization or combustion of landfill gas; Cut off the flood discharge ditch around the site to prevent the flood from entering the site. ?