The problem: Answer a question about this article:
The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient sacrificial anode in cathodic protection (CP). For example, cathodic protection of a buried pipeline can be achieved by connecting anodes made from zinc to the pipe. Zinc acts as the anode (negative terminus) by slowly corroding away as it passes electric current to the steel pipeline.[note 2] Zinc is also used to cathodically protect metals that are exposed to sea water from corrosion. A zinc disc attached to a ship's iron rudder will slowly corrode, whereas the rudder stays unattacked. Other similar uses include a plug of zinc attached to a propeller or the metal protective guard for the keel of the ship.
Why does zinc protect metals exposed to sea water from corroding?
****
The answer: will slowly corrode, whereas the rudder stays unattacked

The problem: Answer a question about this article:
Following the 197475 Loans Affair, the Malcolm Fraser led Liberal-Country Party Coalition argued that the Whitlam Government was incompetent and delayed passage of the Government's money bills in the Senate, until the government would promise a new election. Whitlam refused, Fraser insisted leading to the divisive 1975 Australian constitutional crisis. The deadlock came to an end when the Whitlam government was dismissed by the Governor-General, Sir John Kerr on 11 November 1975 and Fraser was installed as caretaker Prime Minister, pending an election. Fraser won in a landslide at the resulting 1975 election.
On what day did the 1975 constitutional crisis deadlock end?
****
The answer: 11 November 1975

The problem: Answer a question about this article:
Erich Koch headed the East Prussian Nazi party from 1928. He led the district from 1932. This period was characterized by efforts to collectivize the local agriculture and ruthlessness in dealing with his critics inside and outside the Party. He also had long-term plans for mass-scale industrialization of the largely agricultural province. These actions made him unpopular among the local peasants. In 1932 the local paramilitary SA had already started to terrorise their political opponents. On the night of 31 July 1932 there was a bomb attack on the headquarters of the Social Democrats in Konigsberg, the Otto-Braun-House. The Communist politician Gustav Sauf was killed; the executive editor of the Social Democrat "Konigsberger Volkszeitung", Otto Wyrgatsch, and the German People's Party politician Max von Bahrfeldt were severely injured. Members of the Reichsbanner were attacked and the local Reichsbanner Chairman of Lotzen, Kurt Kotzan, was murdered on 6 August 1932.
Who was killed in the attack of the Social Democrats?
****
The answer: Gustav Sauf

The problem: Answer a question about this article:
The Scheinergrade (Sch.) system was devised by the German astronomer Julius Scheiner (18581913) in 1894 originally as a method of comparing the speeds of plates used for astronomical photography. Scheiner's system rated the speed of a plate by the least exposure to produce a visible darkening upon development. Speed was expressed in degrees Scheiner, originally ranging from 1 Sch. to 20 Sch., where an increment of 19 Sch. corresponded to a hundredfold increase in sensitivity, which meant that an increment of 3 Sch. came close to a doubling of sensitivity.
Who created the Scheinergrade system?
****
The answer:
the German astronomer Julius Scheiner