Question: The Portuguese explorer Diogo Cao reached the mouth of the Congo in 1484. Commercial relationships quickly grew between the inland Bantu kingdoms and European merchants who traded various commodities, manufactured goods, and people captured from the hinterlands. After centuries as a major hub for transatlantic trade, direct European colonization of the Congo river delta began in the late 19th century, subsequently eroding the power of the Bantu societies in the region.
Is there an answer to this question: Whose expedition arrived at the mouth of the Congo River in 1484?

Answer: Diogo Cao

Question: A literary technique or literary device can be used by authors in order to enhance the written framework of a piece of literature, and produce specific effects. Literary techniques encompass a wide range of approaches to crafting a work: whether a work is narrated in first-person or from another perspective, whether to use a traditional linear narrative or a nonlinear narrative, or the choice of literary genre, are all examples of literary technique. They may indicate to a reader that there is a familiar structure and presentation to a work, such as a conventional murder-mystery novel; or, the author may choose to experiment with their technique to surprise the reader.
Is there an answer to this question: What is a familiar structure is an example of?

Answer: unanswerable

Question: The formation of the party was formally announced at Sydney Town Hall on 31 August 1945. It took the name "Liberal" in honour of the old Commonwealth Liberal Party. The new party was dominated by the remains of the old UAP; with few exceptions, the UAP party room became the Liberal party room. The Australian Women's National League, a powerful conservative women's organisation, also merged with the new party. A conservative youth group Menzies had set up, the Young Nationalists, was also merged into the new party. It became the nucleus of the Liberal Party's youth division, the Young Liberals. By September 1945 there were more than 90,000 members, many of whom had not previously been members of any political party.
Is there an answer to this question: Where was the formation of the Liberal party officially announced?

Answer: Sydney Town Hall

Question: DC commutating electric motors, if fitted with laminated pole pieces, become universal motors because they can also operate on AC; reversing the current in both stator and rotor does not reverse the motor. But the now-standard AC distribution frequencies of 50 and 60 Hz caused difficulties with inductive reactance and eddy current losses. Many railways chose low AC frequencies to overcome these problems. They must be converted from utility power by motor-generators or static inverters at the feeding substations or generated at dedicated traction powerstations.
Is there an answer to this question: How do railways try to solve the problem of inductive reactance of AC system?

Answer:
low AC frequencies