Problem: Communication:

The broad field of animal communication encompasses most of the issues in ethology. Animal communication can be defined as any behavior of one animal that affects the current or future behavior of another animal. The study of animal communication, called zoo semiotics (distinguishable from anthroposemiotics, the study of human communication) has played an important part in the development of ethology, sociobiology, and the study of animal cognition. Animal communication, and indeed the understanding of the animal world in general, is a rapidly growing field, and even in the 21st century so far, a great share of prior understanding related to diverse fields such as personal symbolic name use, animal emotions, animal culture and learning, and even sexual conduct, long thought to be well understood, has been revolutionized. A special field of animal communication has been investigated in more detail such as vibrational communication.

How is animal communication defined?
---
A: any behavior of one animal that affects the current or future behavior of another animal


Problem: The Republic of Letters was the sum of a number of Enlightenment ideals: an egalitarian realm governed by knowledge that could act across political boundaries and rival state power. It was a forum that supported "free public examination of questions regarding religion or legislation". Immanuel Kant considered written communication essential to his conception of the public sphere; once everyone was a part of the "reading public", then society could be said to be enlightened. The people who participated in the Republic of Letters, such as Diderot and Voltaire, are frequently known today as important Enlightenment figures. Indeed, the men who wrote Diderot's Encyclopédie arguably formed a microcosm of the larger "republic".
Who were two of the figures that participated in the Republic of Letters?
---
Answer: Diderot and Voltaire


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The city shares a 15-mile (24 km) border with Mexico that includes two border crossings. San Diego hosts the busiest international border crossing in the world, in the San Ysidro neighborhood at the San Ysidro Port of Entry. A second, primarily commercial border crossing operates in the Otay Mesa area; it is the largest commercial crossing on the California-Baja California border and handles the third-highest volume of trucks and dollar value of trade among all United States-Mexico land crossings.
How long is the border that San Diego shares with Mexico?
A: 15-mile (24 km)


Context and question: Midtown Raleigh is a residential and commercial area just North of the I-440 Beltline and is part of North Raleigh. It is roughly framed by Glenwood/Creedmoor Road to the West, Wake Forest Road to the East, and Millbrook Road to the North. It includes shopping centers such as North Hills and Crabtree Valley Mall. It also includes North Hills Park and part of the Raleigh Greenway System. The term was coined by the Greater Raleigh Chamber of Commerce, developer John Kane and planning director Mitchell Silver. The News & Observer newspaper started using the term for marketing purposes only. The Midtown Raleigh Alliance was founded on July 25, 2011 as a way for community leaders to promote the area.
Where is the South Hills Shopping center located?
Answer: unanswerable


Question: By 390 BC, several Gallic tribes were invading Italy from the north as their culture expanded throughout Europe. The Romans were alerted to this when a particularly warlike tribe invaded two Etruscan towns close to Rome's sphere of influence. These towns, overwhelmed by the enemy's numbers and ferocity, called on Rome for help. The Romans met the Gauls in pitched battle at the Battle of Allia River around 390–387 BC. The Gauls, led by chieftain Brennus, defeated the Roman army of approximately 15,000 troops, pursued the fleeing Romans back to Rome, and sacked the city before being either driven off or bought off. Romans and Gauls continued to war intermittently in Italy for more than two centuries.[relevant? – discuss]
Is there an answer to this question: How many of the Roman military were involved in the Battle of Allia River?

Answer: 15,000 troops


Problem: Mandolin:

These styles generally have either two f-shaped soundholes like a violin (F-5 and A-5), or an oval sound hole (F-4 and A-4 and lower models) directly under the strings. Much variation exists between makers working from these archetypes, and other variants have become increasingly common. Generally, in the United States, Gibson F-hole F-5 mandolins and mandolins influenced by that design are strongly associated with bluegrass, while the A-style is associated other types of music, although it too is most often used for and associated with bluegrass. The F-5's more complicated woodwork also translates into a more expensive instrument.

Why is the F-5 mandolin more expensive?
---
A:
complicated woodwork