QUES: In addressing the question of who invented the incandescent lamp, historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan and Thomas Edison. They conclude that Edison's version was able to outstrip the others because of a combination of three factors: an effective incandescent material, a higher vacuum than others were able to achieve (by use of the Sprengel pump) and a high resistance that made power distribution from a centralized source economically viable.

Which historians wrote about the advantages of Edison's lamp over other early versions?
What is the answer?
ANS: Robert Friedel and Paul Israel
QUES: 1762 brought two new countries into the war. Britain declared war against Spain on 4 January 1762; Spain reacted by issuing their own declaration of war against Britain on 18 January. Portugal followed by joining the war on Britain's side. Spain, aided by the French, launched an invasion of Portugal and succeeded in capturing Almeida. The arrival of British reinforcements stalled a further Spanish advance, and the Battle of Valencia de Alcantara saw British-Portuguese forces overrun a major Spanish supply base. The invaders were stopped on the heights in front of Abrantes (called the pass to Lisbon) where the Anglo-Portuguese were entrenched. Eventually the Anglo-Portuguese army, aided by guerrillas and practicing a scorched earth strategy, chased the greatly reduced Franco-Spanish army back to Spain, recovering almost all the lost towns, among them the Spanish headquarters in Castelo Branco full of wounded and sick that had been left behind.

What city was captured in the first Spain-Portugal conflict?
What is the answer?
ANS: . Spain, aided by the French, launched an invasion of Portugal and succeeded in capturing Almeida
QUES: The coats of domestic dogs are of two varieties: "double" being common with dogs (as well as wolves) originating from colder climates, made up of a coarse guard hair and a soft down hair, or "single", with the topcoat only.

What is the more common coat for dogs from colder climates?
What is the answer?
ANS:
double