Question: While the use of iron started to become more widespread around 1200 BC, mainly because of interruptions in the trade routes for tin, the metal is much softer than bronze. However, very small amounts of steel, (an alloy of iron and around 1% carbon), was always a byproduct of the bloomery process. The ability to modify the hardness of steel by heat treatment had been known since 1100 BC, and the rare material was valued for the manufacture of tools and weapons. Because the ancients could not produce temperatures high enough to melt iron fully, the production of steel in decent quantities did not occur until the introduction of blister steel during the Middle Ages. This method introduced carbon by heating wrought iron in charcoal for long periods of time, but the penetration of carbon was not very deep, so the alloy was not homogeneous. In 1740, Benjamin Huntsman began melting blister steel in a crucible to even out the carbon content, creating the first process for the mass production of tool steel. Huntsman's process was used for manufacturing tool steel until the early 1900s.
Try to answer this question if possible: What became more widespread in 1280 BC? 
Answer: unanswerable
Question: The Central Bank of Liberia is responsible for printing and maintaining the Liberian dollar, which is the primary form of currency in Liberia. Liberia is one of the world's poorest countries, with a formal employment rate of 15%. GDP per capita peaked in 1980 at US$496, when it was comparable to Egypt's (at the time). In 2011, the country's nominal GDP was US$1.154 billion, while nominal GDP per capita stood at US$297, the third-lowest in the world. Historically, the Liberian economy has depended heavily on foreign aid, foreign direct investment and exports of natural resources such as iron ore, rubber and timber.
Try to answer this question if possible: What is Liberia considered around the world economically? 
Answer: one of the world's poorest countries
Question: Into the first half of the twentieth century after the establishment of ROC, Nanjing gradually shifted from being a production hub towards being a heavy consumption city, mainly because of the rapid expansion of its wealthy population after Nanjing once again regained the political spotlight of China. A number of huge department stores such as Zhongyang Shangchang sprouted up, attracting merchants from all over China to sell their products in Nanjing. In 1933, the revenue generated by the food and entertainment industry in the city exceeded the sum of the output of the manufacturing and agriculture industry. One third of the city population worked in the service industry, .
Try to answer this question if possible: In what time period did Nanjing transform from a producer to more of a consumer city?
Answer: Into the first half of the twentieth century
Question: Spanish colonization commenced on June 15, 1668 with the arrival of Diego Luis de San Vitores and Pedro Calungsod, who established the first Catholic church.:64 The islands were part of the Spanish East Indies governed from the Philippines, which were in turn part of the Viceroyalty of New Spain based in Mexico City. Other reminders of colonial times include the old Governor's Palace in Plaza de España and the Spanish Bridge, both in Hagatña. Guam's Cathedral Dulce Nombre de Maria was formally opened on February 2, 1669, as was the Royal College of San Juan de Letran.:68 Guam, along with the rest of the Mariana and Caroline Islands, were treated as part of Spain's colony in the Philippines. While Guam's Chamorro culture has indigenous roots, the cultures of both Guam and the Northern Marianas have many similarities with Spanish and Mexican culture due to three centuries of Spanish rule.
Try to answer this question if possible: On what date did Spain colonize the Philippines?
Answer:
unanswerable