Problem: The Palácio da Alvorada is the official residence of the President of Brazil. The palace was designed, along with the rest of the city of Brasília, by Oscar Niemeyer and inaugurated in 1958. One of the first structures built in the republic's new capital city, the "Alvorada" lies on a peninsula at the margins of Lake Paranoá. The principles of simplicity and modernity, that in the past characterized the great works of architecture, motivated Niemeyer. The viewer has an impression of looking at a glass box, softly landed on the ground with the support of thin external columns. The building has an area of 7,000 m2 with three floors consisting of the basement, landing, and second floor. The auditorium, kitchen, laundry, medical center, and administration offices are at basement level. The rooms used by the presidency for official receptions are on the landing. The second floor has four suites, two apartments, and various private rooms which make up the residential part of the palace. The building also has a library, a heated Olympic-sized swimming pool, a music room, two dining rooms and various meeting rooms. A chapel and heliport are in adjacent buildings.
How large is the Alvorada?
The answer is the following: 7,000 m2

Problem: The hourglass uses the flow of sand to measure the flow of time. They were used in navigation. Ferdinand Magellan used 18 glasses on each ship for his circumnavigation of the globe (1522). Incense sticks and candles were, and are, commonly used to measure time in temples and churches across the globe. Waterclocks, and later, mechanical clocks, were used to mark the events of the abbeys and monasteries of the Middle Ages. Richard of Wallingford (1292–1336), abbot of St. Alban's abbey, famously built a mechanical clock as an astronomical orrery about 1330. Great advances in accurate time-keeping were made by Galileo Galilei and especially Christiaan Huygens with the invention of pendulum driven clocks along with the invention of the minute hand by Jost Burgi.
Which device uses the flow of sand to measure time?
The answer is the following: The hourglass

Problem: Scholars disagree over the effects of social status on racial classifications in Brazil. It is generally believed that achieving upward mobility and education results in individuals being classified as a category of lighter skin. The popular claim is that in Brazil, poor whites are considered black and wealthy blacks are considered white. Some scholars disagree, arguing that "whitening" of one's social status may be open to people of mixed race, a large part of the population known as pardo, but a person perceived as preto (black) will continue to be classified as black regardless of wealth or social status.
What does Preto mean?
The answer is the following: (black)

Problem: National park and nature reserve is the area selected by governments or private organizations for special protection against damage or degradation with the objective of biodiversity and landscape conservation. National parks are usually owned and managed by national or state governments. A limit is placed on the number of visitors permitted to enter certain fragile areas. Designated trails or roads are created. The visitors are allowed to enter only for study, cultural and recreation purposes. Forestry operations, grazing of animals and hunting of animals are prohibited. Exploitation of habitat or wildlife is banned.
What activities are prohibited in national parks?
The answer is the following:
Forestry operations, grazing of animals and hunting of animals