Problem: In the far north, there is a division between Berber-descendent Tuareg nomad populations and the darker-skinned Bella or Tamasheq people, due the historical spread of slavery in the region. An estimated 800,000 people in Mali are descended from slaves. Slavery in Mali has persisted for centuries. The Arabic population kept slaves well into the 20th century, until slavery was suppressed by French authorities around the mid-20th century. There still persist certain hereditary servitude relationships, and according to some estimates, even today approximately 200,000 Malians are still enslaved.
What region of the country is historical slavery well known?
The answer is the following: far north

Problem: The Reconquista of Portugal and Spain led to a series of oceanic explorations resulting in the Age of Discovery that established direct links with Africa, the Americas, and Asia, while religious wars continued to be fought in Europe, which ended in 1648 with the Peace of Westphalia. The Spanish crown maintained its hegemony in Europe and was the leading power on the continent until the signing of the Treaty of the Pyrenees, which ended a conflict between Spain and France that had begun during the Thirty Years' War. An unprecedented series of major wars and political revolutions took place around Europe and indeed the world in the period between 1610 and 1700. Observers at the time, and many historians since, have argued that wars caused the revolutions. Galileo Galilei, invented the telescope and the thermometer which allowed him to observe and describe the solar system. Leonardo da Vinci painted the most famous work in the world. Guglielmo Marconi invented the radio.
Between which two nations was the Treaty of the Pyrenees signed?
The answer is the following: Spain and France

Problem: Starting in 1940 (18 months before Pearl Harbor), the nation mobilized, giving high priority to air power. American involvement in World War II in 194041 was limited to providing war material and financial support to Britain, the Soviet Union, and the Republic of China. The U.S. entered officially on 8 December 1941 following the Japanese attack on Pearl Harbor, Hawaii. Japanese forces soon seized American, Dutch, and British possessions across the Pacific and Southeast Asia, except for Australia, which became a main American forward base along with Hawaii.
At the start of the conflict with the Allies, what did Japan do?
The answer is the following: seized American, Dutch, and British possessions across the Pacific and Southeast Asia

Problem: In about 260 AD, the fall of the Agri Decumates territory north of the Rhine transformed today's Switzerland into a frontier land of the Empire. Repeated raids by the Alamanni tribes provoked the ruin of the Roman towns and economy, forcing the population to find shelter near Roman fortresses, like the Castrum Rauracense near Augusta Raurica. The Empire built another line of defense at the north border (the so-called Donau-Iller-Rhine-Limes), but at the end of the fourth century the increased Germanic pressure forced the Romans to abandon the linear defence concept, and the Swiss plateau was finally open to the settlement of German tribes.
Who was allowed to settle on the Swiss plateau by the end of the 4th century?
The answer is the following:
German tribes