Problem: With the introduction of the blast furnace to Europe in the Middle Ages, pig iron was able to be produced in much higher volumes than wrought iron. Because pig iron could be melted, people began to develop processes of reducing the carbon in the liquid pig iron to create steel. Puddling was introduced during the 1700s, where molten pig iron was stirred while exposed to the air, to remove the carbon by oxidation. In 1858, Sir Henry Bessemer developed a process of steel-making by blowing hot air through liquid pig iron to reduce the carbon content. The Bessemer process was able to produce the first large scale manufacture of steel. Once the Bessemer process began to gain widespread use, other alloys of steel began to follow. Mangalloy, an alloy of steel and manganese exhibiting extreme hardness and toughness, was one of the first alloy steels, and was created by Robert Hadfield in 1882.
What did the blast furnace help do to pig iron in the middle ages?
The answer is the following: produced in much higher volumes than wrought iron

Problem: For various reasons, the new firm operated as a dual-listed company, whereby the merging companies maintained their legal existence, but operated as a single-unit partnership for business purposes. The terms of the merger gave 60 percent ownership of the new group to the Dutch arm and 40 percent to the British. National patriotic sensibilities would not permit a full-scale merger or takeover of either of the two companies. The Dutch company, Koninklijke Nederlandsche Petroleum Maatschappij, was in charge at The Hague of production and manufacture. A British company was formed, called the Anglo-Saxon Petroleum Company, based in London, to direct the transport and storage of the products.
The new firm operated as what type of company?
The answer is the following: a dual-listed company

Problem: Guinea-Bissau was once part of the kingdom of Gabu, part of the Mali Empire; parts of this kingdom persisted until the 18th century. Other parts of the territory in the current country were considered by the Portuguese as part of their empire. Portuguese Guinea was known as the Slave Coast, as it was a major area for the exportation of African slaves by Europeans to the western hemisphere. Previously slaves had been traded by Arabs north to the northern part of Africa and into the Middle East.
Who traded slaves into the Middle East?
The answer is the following: Arabs

Problem: Solar distillation can be used to make saline or brackish water potable. The first recorded instance of this was by 16th-century Arab alchemists. A large-scale solar distillation project was first constructed in 1872 in the Chilean mining town of Las Salinas. The plant, which had solar collection area of 4,700 m2 (51,000 sq ft), could produce up to 22,700 L (5,000 imp gal; 6,000 US gal) per day and operate for 40 years. Individual still designs include single-slope, double-slope (or greenhouse type), vertical, conical, inverted absorber, multi-wick, and multiple effect. These stills can operate in passive, active, or hybrid modes. Double-slope stills are the most economical for decentralized domestic purposes, while active multiple effect units are more suitable for large-scale applications.
What is used to make saline or brackish water drinkable?
The answer is the following:
Solar distillation