Here is a question about this article: In September 1828 Chopin, while still a student, visited Berlin with a family friend, zoologist Feliks Jarocki, enjoying operas directed by Gaspare Spontini and attending concerts by Carl Friedrich Zelter, Felix Mendelssohn and other celebrities. On an 1829 return trip to Berlin, he was a guest of Prince Antoni Radziwiłł, governor of the Grand Duchy of Posen—himself an accomplished composer and aspiring cellist. For the prince and his pianist daughter Wanda, he composed his Introduction and Polonaise brillante in C major for cello and piano, Op. 3.
What is the answer to this question: What year did Chopin return to Berlin?
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So... 1829


Here is a question about this article: Most organisms studied to date utilize a reward–punishment mechanism: for instance, worms and insects can alter their behavior to seek food sources or to avoid dangers. In vertebrates, the reward-punishment system is implemented by a specific set of brain structures, at the heart of which lie the basal ganglia, a set of interconnected areas at the base of the forebrain. There is substantial evidence that the basal ganglia are the central site at which decisions are made: the basal ganglia exert a sustained inhibitory control over most of the motor systems in the brain; when this inhibition is released, a motor system is permitted to execute the action it is programmed to carry out. Rewards and punishments function by altering the relationship between the inputs that the basal ganglia receive and the decision-signals that are emitted. The reward mechanism is better understood than the punishment mechanism, because its role in drug abuse has caused it to be studied very intensively. Research has shown that the neurotransmitter dopamine plays a central role: addictive drugs such as cocaine, amphetamine, and nicotine either cause dopamine levels to rise or cause the effects of dopamine inside the brain to be enhanced.
What is the answer to this question: Which neurotransmitter plays a large role in drug abuse?
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So... dopamine


Here is a question about this article: The development of writing is counted among the many achievements and innovations of pre-Columbian American cultures. Independent from the development of writing in other areas of the world, the Mesoamerican region produced several indigenous writing systems beginning in the 1st millennium BCE. What may be the earliest-known example in the Americas of an extensive text thought to be writing is by the Cascajal Block. The Olmec hieroglyphs tablet has been indirectly dated from ceramic shards found in the same context to approximately 900 BCE, around the time that Olmec occupation of San Lorenzo Tenochtitlán began to wane.
What is the answer to this question: When has the Olmec tablet been dated to?
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So...
900 BCE