Stream of consciousness: The relevant information is: Salman bin Abdulaziz Al Saud (Arabic: سلمان بن عبد العزیز آل سعود ‎ Salmān ibn' Abd al -' Azīz Āl Sa'ūd Arabic pronunciation: ( sæɫmæːn ibˈn ʕabˈduɫ ʕaziːz æːɫ saʕuːd); born 31 December 1935 ) is a Saudi Arabian politician and royal statesman who has been King of Saudi Arabia, Prime Minister, Custodian of the Two Holy Mosques and head of the House of Saud since 2015.
Q: Salman bin Abdulaziz Al Saud (Arabic: سلمان بن عبد العزیز آل سعود ‎ Salmān ibn' Abd al -' Azīz Āl Sa'ūd Arabic pronunciation: ( sæɫmæːn ibˈn ʕabˈduɫ ʕaziːz æːɫ saʕuːd); born 31 December 1935 ) is a Saudi Arabian politician and royal statesman who has been King of Saudi Arabia, Prime Minister, Custodian of the Two Holy Mosques and head of the House of Saud since 2015.

Answer this question based on the passage: who is the current leader of saudi arabia?
A: Salman bin Abdulaziz Al Saud

Stream of consciousness: To answer the question, consider the following: It was first protected as a U.S. National Monument on December 1, 1978, before becoming a national park and preserve two years later in 1980 upon passage of the Alaska National Interest Lands Conservation Act.
Q: Gates of the Arctic National Park and Preserve is a U.S. National Park in Alaska. It is the northernmost national park in the U.S. (the entirety of the park lies north of the Arctic Circle) and the second largest at 8,472,506 acres (3,428,702 ha) (34,287 km2), slightly larger in area than Belgium. The park consists primarily of portions of the Brooks Range of mountains. It was first protected as a U.S. National Monument on December 1, 1978, before becoming a national park and preserve two years later in 1980 upon passage of the Alaska National Interest Lands Conservation Act. A large part of the park is protected in the Gates of the Arctic Wilderness which covers 7,167,192 acres (2,900,460 ha). The wilderness area adjoins the Noatak Wilderness Area and together they form the largest contiguous wilderness in the United States.

When did gates of the arctic become a national park?
A: 1980

Stream of consciousness: To answer the question, consider the following: The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BCE by Aristarchus of Samos, but at least in the medieval world, Aristarchus's Heliocentrism attracted little attention -- possibly because of the loss of scientific works of the Hellenistic Era.

Q: Context: Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System. Historically, Heliocentrism was opposed to geocentrism, which placed the Earth at the center. The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BCE by Aristarchus of Samos, but at least in the medieval world, Aristarchus's Heliocentrism attracted little attention -- possibly because of the loss of scientific works of the Hellenistic Era.

Question: who said sun is the center of the solar system?
A: Aristarchus of Samos