Problem: In the dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles (interfascicular cambium), a complete ring is formed, and a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside. The soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.
What is a layer of meristem or formative tissue known as?
The answer is the following: cambium

Problem: In addition to the above, Greece is also to start oil and gas exploration in other locations in the Ionian Sea, as well as the Libyan Sea, within the Greek exclusive economic zone, south of Crete. The Ministry of the Environment, Energy and Climate Change announced that there was interest from various countries (including Norway and the United States) in exploration, and the first results regarding the amount of oil and gas in these locations were expected in the summer of 2012. In November 2012, a report published by Deutsche Bank estimated the value of natural gas reserves south of Crete at 427 billion.
What did the Deutsche Bank estimate the value of the reserves to be at?
The answer is the following: 427 billion

Problem: European maps continued to show this hypothesized land until Captain James Cook's ships, HMS Resolution and Adventure, crossed the Antarctic Circle on 17 January 1773, in December 1773 and again in January 1774. Cook came within about 120 km (75 mi) of the Antarctic coast before retreating in the face of field ice in January 1773. The first confirmed sighting of Antarctica can be narrowed down to the crews of ships captained by three individuals. According to various organizations (the National Science Foundation, NASA, the University of California, San Diego, and other sources), ships captained by three men sighted Antarctica or its ice shelf in 1820: von Bellingshausen (a captain in the Imperial Russian Navy), Edward Bransfield (a captain in the Royal Navy), and Nathaniel Palmer (a sealer out of Stonington, Connecticut). The expedition led by von Bellingshausen and Lazarev on the ships Vostok and Mirny reached a point within 32 km (20 mi) from Queen Maud's Land and recorded the sight of an ice shelf at 692128S 21450W / 69.35778S 2.24722W / -69.35778; -2.24722, which became known as the Fimbul ice shelf. This happened three days before Bransfield sighted land, and ten months before Palmer did so in November 1820. The first documented landing on Antarctica was by the American sealer John Davis, apparently at Hughes Bay, near Cape Charles, in West Antarctica on 7 February 1821, although some historians dispute this claim. The first recorded and confirmed landing was at Cape Adair in 1895.
When was the first recorded landing on Antarctica?
The answer is the following: 1895

Problem: Hydrogen gas was first artificially produced in the early 16th century, via the mixing of metals with acids. In 176681, Henry Cavendish was the first to recognize that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name: in Greek, hydrogen means "water-former".
When was hydrogen gas artificially produced for the first time?
The answer is the following:
early 16th century