Question: Orientation behaviour studies have been traditionally carried out using variants of a setup known as the Emlen funnel, which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.
Is there an answer to this question: What shape is the cage in the Emlen funnel?

Answer: circular


Question: The Vietnam War was a war fought between 1959 and 1975 on the ground in South Vietnam and bordering areas of Cambodia and Laos (see Secret War) and in the strategic bombing (see Operation Rolling Thunder) of North Vietnam. American advisors came in the late 1950s to help the RVN (Republic of Vietnam) combat Communist insurgents known as "Viet Cong." Major American military involvement began in 1964, after Congress provided President Lyndon B. Johnson with blanket approval for presidential use of force in the Gulf of Tonkin Resolution.
Is there an answer to this question:  Besides China, what other countries saw fighting in this war?

Answer: unanswerable


Question: In 1997, a year after the divorce, Diana was killed in a car crash in Paris. The Queen was on holiday with her extended family at Balmoral. Diana's two sons by Charles—Princes William and Harry—wanted to attend church and so the Queen and Prince Philip took them that morning. After that single public appearance, for five days the Queen and the Duke shielded their grandsons from the intense press interest by keeping them at Balmoral where they could grieve in private, but the royal family's seclusion and the failure to fly a flag at half-mast over Buckingham Palace caused public dismay. Pressured by the hostile reaction, the Queen agreed to return to London and do a live television broadcast on 5 September, the day before Diana's funeral. In the broadcast, she expressed admiration for Diana and her feelings "as a grandmother" for the two princes. As a result, much of the public hostility evaporated.
Is there an answer to this question: What incident killed Diana in Paris?

Answer: car crash


Question: The main active ingredient of beer is alcohol, and therefore, the health effects of alcohol apply to beer. Consumption of small quantities of alcohol (less than one drink in women and two in men) is associated with a decreased risk of cardiac disease, stroke and diabetes mellitus. The long term health effects of continuous, moderate or heavy alcohol consumption include the risk of developing alcoholism and alcoholic liver disease. A total of 3.3 million deaths (5.9% of all deaths) are believed to be due to alcohol. Alcoholism often reduces a person's life expectancy by around ten years. Alcohol use is the third leading cause of early death in the United States.
Is there an answer to this question: How many years are removed from an alcoholic's life expectancy?

Answer:
around ten