Problem: Extract the answer to the question from the following context. Question: What country attacked the US? Context: After the Japanese attack on Pearl Harbor, Eisenhower was assigned to the General Staff in Washington, where he served until June 1942 with responsibility for creating the major war plans to defeat Japan and Germany. He was appointed Deputy Chief in charge of Pacific Defenses under the Chief of War Plans Division (WPD), General Leonard T. Gerow, and then succeeded Gerow as Chief of the War Plans Division. Next, he was appointed Assistant Chief of Staff in charge of the new Operations Division (which replaced WPD) under Chief of Staff General George C. Marshall, who spotted talent and promoted accordingly.

A: Japan

Problem: Extract the answer to the question from the following context. Question: How is the data on a CD-RW accessed? Context: Firstly conceived and still used today for optical storage devices (CD-RW drives, DVD drives, etc.), several manufacturers offer external portable USB hard disk drives, or empty enclosures for disk drives. These offer performance comparable to internal drives, limited by the current number and types of attached USB devices, and by the upper limit of the USB interface (in practice about 30 MB/s for USB 2.0 and potentially 400 MB/s or more for USB 3.0). These external drives typically include a "translating device" that bridges between a drive's interface to a USB interface port. Functionally, the drive appears to the user much like an internal drive. Other competing standards for external drive connectivity include eSATA, ExpressCard, FireWire (IEEE 1394), and most recently Thunderbolt.

A: optical

Problem: Extract the answer to the question from the following context. Question: Why might someone not want to power a DC motor using AC current? Context: Operating at normal power line frequencies, universal motors are often found in a range less than 1000 watts. Universal motors also formed the basis of the traditional railway traction motor in electric railways. In this application, the use of AC to power a motor originally designed to run on DC would lead to efficiency losses due to eddy current heating of their magnetic components, particularly the motor field pole-pieces that, for DC, would have used solid (un-laminated) iron and they are now rarely used.

A: efficiency losses

Problem: Extract the answer to the question from the following context. Question: What happened to Virgil's Poem? Context: According to the tradition, Virgil traveled to Greece in about 19 BC to revise the Aeneid. After meeting Augustus in Athens and deciding to return home, Virgil caught a fever while visiting a town near Megara. After crossing to Italy by ship, weakened with disease, Virgil died in Brundisium harbor on September 21, 19 BC. Augustus ordered Virgil's literary executors, Lucius Varius Rufus and Plotius Tucca, to disregard Virgil's own wish that the poem be burned, instead ordering it published with as few editorial changes as possible. As a result, the text of the Aeneid that exists may contain faults which Virgil was planning to correct before publication. However, the only obvious imperfections are a few lines of verse that are metrically unfinished (i.e. not a complete line of dactylic hexameter). Some scholars have argued that Virgil deliberately left these metrically incomplete lines for dramatic effect. Other alleged imperfections are subject to scholarly debate.

A:
published