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.
PetroChina is the fifth largest oil and gas company in the world. It produced 916.5 million barrels of crude oil and 2.558 trillion cubic feet of natural gas in 2012. Overseas crude oil production by the company during the year stood at 136.9 million barrels.