Problem: In 1972, the French physicist Francis Perrin discovered fifteen ancient and no longer active natural nuclear fission reactors in three separate ore deposits at the Oklo mine in Gabon, West Africa, collectively known as the Oklo Fossil Reactors. The ore deposit is 1.7 billion years old; then, uranium-235 constituted about 3% of the total uranium on Earth. This is high enough to permit a sustained nuclear fission chain reaction to occur, provided other supporting conditions exist. The capacity of the surrounding sediment to contain the nuclear waste products has been cited by the U.S. federal government as supporting evidence for the feasibility to store spent nuclear fuel at the Yucca Mountain nuclear waste repository.
How old are the ore deposits in the Oklo mine?
The answer is the following: 1.7 billion years

Problem: While medieval pageants and festivals such as Corpus Christi were church-sanctioned, Carnival was also a manifestation of medieval folk culture. Many local Carnival customs are claimed to derive from local pre-Christian rituals, such as elaborate rites involving masked figures in the Swabian–Alemannic Fastnacht. However, evidence is insufficient to establish a direct origin from Saturnalia or other ancient festivals. No complete accounts of Saturnalia survive and the shared features of feasting, role reversals, temporary social equality, masks and permitted rule-breaking do not necessarily constitute a coherent festival or link these festivals. These similarities may represent a reservoir of cultural resources that can embody multiple meanings and functions. For example, Easter begins with the resurrection of Jesus, followed by a liminal period and ends with rebirth. Carnival reverses this as King Carnival comes to life, a liminal period follows before his death. Both feasts are calculated by the lunar calendar. Both Jesus and King Carnival may be seen as expiatory figures who make a gift to the people with their deaths. In the case of Jesus, the gift is eternal life in heaven and in the case of King Carnival, the acknowledgement that death is a necessary part of the cycle of life. Besides Christian anti-Judaism, the commonalities between church and Carnival rituals and imagery suggest a common root. Christ's passion is itself grotesque: Since early Christianity Christ is figured as the victim of summary judgement, is tortured and executed by Romans before a Jewish mob ("His blood is on us and on our children!" Matthew 27:24–25). Holy Week processions in Spain include crowds who vociferously insult the figure of Jesus. Irreverence, parody, degradation and laughter at a tragicomic effigy God can be seen as intensifications of the sacred order. In 1466, the Catholic Church under Pope Paul II revieved customs of the Saturnalia carnival: Jews were forced to race naked through the streets of the city of Rome. “Before they were to run, the Jews were richly fed, so as to make the race more difficult for them and at the same time more amusing for spectators. They ran… amid Rome’s taunting shrieks and peals of laughter, while the Holy Father stood upon a richly ornamented balcony and laughed heartily”, an eyewitness reports.
What is insufficient to establish a direct origin from ancient festivals to Carnival?
The answer is the following: evidence

Problem: Interactions between alcohol and certain antibiotics may occur and may cause side-effects and decreased effectiveness of antibiotic therapy. While moderate alcohol consumption is unlikely to interfere with many common antibiotics, there are specific types of antibiotics with which alcohol consumption may cause serious side-effects. Therefore, potential risks of side-effects and effectiveness depend on the type of antibiotic administered. Despite the lack of a categorical counterindication, the belief that alcohol and antibiotics should never be mixed is widespread.
What type of antibiotic is most likely to be a problem with alcohol?
The answer is the following: specific types of antibiotics with which alcohol consumption may cause serious side-effects

Problem: Beginning in 1979, Nigerians participated in a brief return to democracy when Olusegun Obasanjo transferred power to the civilian regime of Shehu Shagari. The Shagari government became viewed as corrupt and incompetent by virtually all sectors of Nigerian society. The military coup of Muhammadu Buhari shortly after the regime's fraudulent re-election in 1984 was generally viewed as a positive development. Buhari promised major reforms, but his government fared little better than its predecessor. His regime was overthrown by another military coup in 1985.
How did Nigerians view the Shagari administration?
The answer is the following:
corrupt and incompetent