Of the six orders of Pulmonata, two â the Onchidiacea and Soleolifera â solely comprise slugs. A third family, the Sigmurethra, contains various clades of snails, semi-slugs (i.e. snails whose shells are too small for them to retract fully into) and slugs. The taxonomy of this group is in the process of being revised in light of DNA sequencing.
Q: How much of the worldâs oil reserves are located in OPEC countries? A: 80% of the world's oil reserves are located in just 13 countries which make up OPEC (the Organization of the Petroleum Exporting Countries). Algeria, Venezuela, Saudi Arabia, Iran, Iraq, Kuwait, Angola, Indonesia, Ecuador, Libya, Nigeria, Qatar, and the United Arab Emirates.
At present many companies have the this business: from extracting oil and gas through pipelines and installation of platforms, to the production of derivatives as fuel and plastics. The worldâs major top oil companies are located in four continents: Asia, Europe, America and Africa. The most important, The Middle East is one of the places where there are large reserves of crude account. There is the half of the worldâs oil reserves: 1.2 billion barrels , approximately.