Problem: Geological history of Earth:

The Carboniferous was a time of active mountain building, as the supercontinent Pangea came together. The southern continents remained tied together in the supercontinent Gondwana, which collided with North America-Europe (Laurussia) along the present line of eastern North America. This continental collision resulted in the Hercynian orogeny in Europe, and the Alleghenian orogeny in North America; it also extended the newly uplifted Appalachians southwestward as the Ouachita Mountains. In the same time frame, much of present eastern Eurasian plate welded itself to Europe along the line of the Ural mountains. There were two major oceans in the Carboniferous the Panthalassa and Paleo-Tethys. Other minor oceans were shrinking and eventually closed the Rheic Ocean (closed by the assembly of South and North America), the small, shallow Ural Ocean (which was closed by the collision of Baltica, and Siberia continents, creating the Ural Mountains) and Proto-Tethys Ocean.

The mountains forming to the southwest of the Appalachians in the Carboniferous are known as what?
---
A: the Ouachita Mountains

Problem: Carnival:

Carnival has been celebrated for centuries. The tradition was likely established under Venetian rule around the 16th century. It may have been influenced by Greek traditions, such as festivities for deities such as Dionysus. The celebration originally involved dressing in costumes and holding masked balls or visiting friends. In the twentieth century it became an organized event held during the 10 days preceding Lent (according to the Greek Orthodox calendar). The festival is celebrated almost exclusively in the city of Limassol.

Under whose rule was Carnival established in the 16th century?
---
A: Venetian

Problem: Punjab, Pakistan:

Punjab's geography mostly consists of the alluvial plain of the Indus River and its four major tributaries in Pakistan, the Jhelum, Chenab, Ravi, and Sutlej rivers. There are several mountainous regions, including the Sulaiman Mountains in the southwest part of the province, and Margalla Hills, Salt Range, and Pothohar Plateau in the north. Agriculture is the chief source of income and employment in Punjab; wheat and cotton are the principal crops. Since independence, Punjab has become the seat of political and economic power; it remains the most industrialised province of Pakistan. It counts for 39.2% of large scale manufacturing and 70% of small scale manufacturing in the country. Its capital Lahore is a major regional cultural, historical, and economic centre.

Which tributary is located in the north?
---
A: unanswerable

Problem: Daylight saving time:

DST has mixed effects on health. In societies with fixed work schedules it provides more afternoon sunlight for outdoor exercise. It alters sunlight exposure; whether this is beneficial depends on one's location and daily schedule, as sunlight triggers vitamin D synthesis in the skin, but overexposure can lead to skin cancer. DST may help in depression by causing individuals to rise earlier, but some argue the reverse. The Retinitis Pigmentosa Foundation Fighting Blindness, chaired by blind sports magnate Gordon Gund, successfully lobbied in 1985 and 2005 for US DST extensions.

What vitamin does sunlight help the human body absorb?
---
A:
vitamin D