Problem: Please answer a question about the following article about Treaty:
Prior to 1871, the government of the United States regularly entered into treaties with Native Americans but the Indian Appropriations Act of March 3, 1871 (ch. 120, 16 Stat. 563) had a rider (25 U.S.C. § 71) attached that effectively ended the President’s treaty making by providing that no Indian nation or tribe shall be acknowledged as an independent nation, tribe, or power with whom the United States may contract by treaty. The federal government continued to provide similar contractual relations with the Indian tribes after 1871 by agreements, statutes, and executive orders.
By what did the US federal government provide contractual relations with Indian tribes following the Indian Appropriations Act of March 3, 1871?
A: agreements, statutes, and executive orders
Problem: Please answer a question about the following article about Alaska:
Some researchers believe that the first Russian settlement in Alaska was established in the 17th century. According to this hypothesis, in 1648 several koches of Semyon Dezhnyov's expedition came ashore in Alaska by storm and founded this settlement. This hypothesis is based on the testimony of Chukchi geographer Nikolai Daurkin, who had visited Alaska in 1764–1765 and who had reported on a village on the Kheuveren River, populated by "bearded men" who "pray to the icons". Some modern researchers associate Kheuveren with Koyuk River.
During which years did Nikolai Durkin visit Alaska?
A: 1764–1765
Problem: Please answer a question about the following article about The Blitz:
German air supremacy at night was also now under threat. British night-fighter operations out over the Channel were proving highly successful. This was not immediately apparent. The Bristol Blenheim F.1 was undergunned, with just four .303 in (7.7 mm) machine guns which struggled to down the Do 17, Ju 88, or Heinkel He 111. Moreover, the Blenheim struggled to reach the speed of the German bombers. Added to the fact an interception relied on visual sighting, a kill was most elusive even in the conditions of a moonlit sky.
How did the Bristol Blenheim F.1 perform against German aircraft?
A: was undergunned, with just four .303 in (7.7 mm) machine guns
Problem: Please answer a question about the following article about Electric motor:
Since the armature windings of a direct-current or universal motor are moving through a magnetic field, they have a voltage induced in them. This voltage tends to oppose the motor supply voltage and so is called "back electromotive force (emf)". The voltage is proportional to the running speed of the motor. The back emf of the motor, plus the voltage drop across the winding internal resistance and brushes, must equal the voltage at the brushes. This provides the fundamental mechanism of speed regulation in a DC motor. If the mechanical load increases, the motor slows down; a lower back emf results, and more current is drawn from the supply. This increased current provides the additional torque to balance the new load.
EMP is proportional to what?
A:
the running speed of the motor