Problem: Prime minister:

By the late 20th century, the majority of the world's countries had a prime minister or equivalent minister, holding office under either a constitutional monarchy or a ceremonial president. The main exceptions to this system have been the United States and the presidential republics in Latin America modelled on the U.S. system, in which the president directly exercises executive authority.

In the U.S. and governments modeled on it, who holds executive power?
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A: president

Problem: The Arctic tern holds the long-distance migration record for birds, travelling between Arctic breeding grounds and the Antarctic each year. Some species of tubenoses (Procellariiformes) such as albatrosses circle the earth, flying over the southern oceans, while others such as Manx shearwaters migrate 14,000 km (8,700 mi) between their northern breeding grounds and the southern ocean. Shorter migrations are common, including altitudinal migrations on mountains such as the Andes and Himalayas.
Where does the Arctic tern migrate each year?
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Answer: between Arctic breeding grounds and the Antarctic

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Agriculture and horticulture seek to optimize the capture of solar energy in order to optimize the productivity of plants. Techniques such as timed planting cycles, tailored row orientation, staggered heights between rows and the mixing of plant varieties can improve crop yields. While sunlight is generally considered a plentiful resource, the exceptions highlight the importance of solar energy to agriculture. During the short growing seasons of the Little Ice Age, French and English farmers employed fruit walls to maximize the collection of solar energy. These walls acted as thermal masses and accelerated ripening by keeping plants warm. Early fruit walls were built perpendicular to the ground and facing south, but over time, sloping walls were developed to make better use of sunlight. In 1699, Nicolas Fatio de Duillier even suggested using a tracking mechanism which could pivot to follow the Sun. Applications of solar energy in agriculture aside from growing crops include pumping water, drying crops, brooding chicks and drying chicken manure. More recently the technology has been embraced by vinters, who use the energy generated by solar panels to power grape presses.
What did French and English farmers do during the Little Ice Age to gain more solar energy?
A: employed fruit walls

Context and question: Legislative power lies with the Nitijela. The upper house of Parliament, called the Council of Iroij, is an advisory body comprising twelve tribal chiefs. The executive branch consists of the President and the Presidential Cabinet, which consists of ten ministers appointed by the President with the approval of the Nitijela. The twenty-four electoral districts into which the country is divided correspond to the inhabited islands and atolls. There are currently four political parties in the Marshall Islands: Aelon Kein Ad (AKA), United People's Party (UPP), Kien Eo Am (KEA) and United Democratic Party (UDP). Rule is shared by the AKA and the UDP. The following senators are in the legislative body:
Who comprises the upper house of the Marshall Islands Parliament?
Answer: twelve tribal chiefs

Question: Most Israelis are drafted into the military at the age of 18. Men serve two years and eight months and women two years. Following mandatory service, Israeli men join the reserve forces and usually do up to several weeks of reserve duty every year until their forties. Most women are exempt from reserve duty. Arab citizens of Israel (except the Druze) and those engaged in full-time religious studies are exempt from military service, although the exemption of yeshiva students has been a source of contention in Israeli society for many years. An alternative for those who receive exemptions on various grounds is Sherut Leumi, or national service, which involves a program of service in hospitals, schools and other social welfare frameworks. As a result of its conscription program, the IDF maintains approximately 176,500 active troops and an additional 445,000 reservists.
Is there an answer to this question: What citizens are exempt from military service?

Answer: Arab citizens

Question: Brass, which is an alloy of copper and zinc, has been used since at least the 10th century BC in Judea and by the 7th century BC in Ancient Greece. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century. The mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc. Alchemists burned zinc in air to form what they called "philosopher's wool" or "white snow".
Is there an answer to this question: Brass is an alloy of what two elements?

Answer:
copper and zinc