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.
Prior to that, in 2014 over 66% of world oil production came from the top ten countries: Saudi Arabia 542 Mt (13%), Russia 529 Mt (13%), United States 509 Mt (12%), China 212 Mt (5%), Canada 208 Mt (5%), Iran 166 Mt (4%), Iraq 160 Mt (4%), Kuwait 158 Mt (4%), United Arab Emirates 157 Mt (4%) and Venezuela 151 Mt (4%).