Problem: Bern is built on very uneven ground. There is an elevation difference of several metres between the inner city districts on the Aare (Matte, Marzili) and the higher ones (Kirchenfeld, Langgasse).
What is the elevation difference between the inner cities and the other cities?
The answer is the following: several metres

Problem: Cancer is now common in developing countries. According to a study by the International Agency for Research on Cancer, "In the developing world, cancers of the liver, stomach and esophagus were more common, often linked to consumption of carcinogenic preserved foods, such as smoked or salted food, and parasitic infections that attack organs." Lung cancer rates are rising rapidly in poorer nations because of increased use of tobacco. Developed countries "tended to have cancers linked to affluence or a 'Western lifestyle' cancers of the colon, rectum, breast and prostate that can be caused by obesity, lack of exercise, diet and age."
Which health issue is now becoming a common issue in developing countries?
The answer is the following: Cancer

Problem: In November 1945, Eisenhower returned to Washington to replace Marshall as Chief of Staff of the Army. His main role was rapid demobilization of millions of soldiers, a slow job that was delayed by lack of shipping. Eisenhower was convinced in 1946 that the Soviet Union did not want war and that friendly relations could be maintained; he strongly supported the new United Nations and favored its involvement in the control of atomic bombs. However, in formulating policies regarding the atomic bomb and relations with the Soviets, Truman was guided by the U.S. State Department and ignored Eisenhower and the Pentagon. Indeed, Eisenhower had opposed the use of the atomic bomb against the Japanese, writing, "First, the Japanese were ready to surrender and it wasn't necessary to hit them with that awful thing. Second, I hated to see our country be the first to use such a weapon." Initially, Eisenhower was characterized by hopes for cooperation with the Soviets. He even visited Warsaw in 1945. Invited by Bolesaw Bierut and decorated with the highest military decoration, he was shocked by the scale of destruction in the city. However, by mid-1947, as EastWest tensions over economic recovery in Germany and the Greek Civil War escalated, Eisenhower gave up and agreed with a containment policy to stop Soviet expansion.
Who was Chief of Staff of the Army before Eisenhower?
The answer is the following: Marshall

Problem: The number of species invasions has been on the rise at least since the beginning of the 1900s. Species are increasingly being moved by humans (on purpose and accidentally). In some cases the invaders are causing drastic changes and damage to their new habitats (e.g.: zebra mussels and the emerald ash borer in the Great Lakes region and the lion fish along the North American Atlantic coast). Some evidence suggests that invasive species are competitive in their new habitats because they are subject to less pathogen disturbance. Others report confounding evidence that occasionally suggest that species-rich communities harbor many native and exotic species simultaneously while some say that diverse ecosystems are more resilient and resist invasive plants and animals. An important question is, "do invasive species cause extinctions?" Many studies cite effects of invasive species on natives, but not extinctions. Invasive species seem to increase local (i.e.: alpha diversity) diversity, which decreases turnover of diversity (i.e.: beta diversity). Overall gamma diversity may be lowered because species are going extinct because of other causes, but even some of the most insidious invaders (e.g.: Dutch elm disease, emerald ash borer, chestnut blight in North America) have not caused their host species to become extinct. Extirpation, population decline, and homogenization of regional biodiversity are much more common. Human activities have frequently been the cause of invasive species circumventing their barriers, by introducing them for food and other purposes. Human activities therefore allow species to migrate to new areas (and thus become invasive) occurred on time scales much shorter than historically have been required for a species to extend its range.
What invaders are causing changes in the Great Lakes region?
The answer is the following:
zebra mussels and the emerald ash borer