Question: Extract the answer to the question from the following context. Question: In the year before 2010, what was the energy production of independent companies? Context: Energy production in Greece is dominated by the Public Power Corporation (known mostly by its acronym ΔΕΗ, or in English DEI). In 2009 DEI supplied for 85.6% of all energy demand in Greece, while the number fell to 77.3% in 2010. Almost half (48%) of DEI's power output is generated using lignite, a drop from the 51.6% in 2009. Another 12% comes from Hydroelectric power plants and another 20% from natural gas. Between 2009 and 2010, independent companies' energy production increased by 56%, from 2,709 Gigawatt hour in 2009 to 4,232 GWh in 2010.
Answer: 2,709

Question: Extract the answer to the question from the following context. Question: What was one shortcoming of early digital computers? Context: Early digital computers were electromechanical; electric switches drove mechanical relays to perform the calculation. These devices had a low operating speed and were eventually superseded by much faster all-electric computers, originally using vacuum tubes. The Z2, created by German engineer Konrad Zuse in 1939, was one of the earliest examples of an electromechanical relay computer.
Answer: low operating speed

Question: Extract the answer to the question from the following context. Question: Who was Demetrius child? Context: After Cassander's death in 298 BCE, however, Demetrius, who still maintained a sizable loyal army and fleet, invaded Macedon, seized the Macedonian throne (294) and conquered Thessaly and most of central Greece (293-291). He was defeated in 288 BC when Lysimachus of Thrace and Pyrrhus of Epirus invaded Macedon on two fronts, and quickly carved up the kingdom for themselves. Demetrius fled to central Greece with his mercenaries and began to build support there and in the northern Peloponnese. He once again laid siege to Athens after they turned on him, but then struck a treaty with the Athenians and Ptolemy, which allowed him to cross over to Asia minor and wage war on Lysimachus' holdings in Ionia, leaving his son Antigonus Gonatas in Greece. After initial successes, he was forced to surrender to Seleucus in 285 and later died in captivity. Lysimachus, who had seized Macedon and Thessaly for himself, was forced into war when Seleucus invaded his territories in Asia minor and was defeated and killed in 281 BCE at the Battle of Corupedium, near Sardis. Seleucus then attempted to conquer Lysimachus' European territories in Thrace and Macedon, but he was assassinated by Ptolemy Ceraunus ("the thunderbolt"), who had taken refuge at the Seleucid court and then had himself acclaimed as king of Macedon. Ptolemy was killed when Macedon was invaded by Gauls in 279, his head stuck on a spear and the country fell into anarchy. Antigonus II Gonatas invaded Thrace in the summer of 277 and defeated a large force of 18,000 Gauls. He was quickly hailed as king of Macedon and went on to rule for 35 years.
Answer:
Antigonus Gonatas