Matthias Broda, inventor and designer of the wooden e-bike, cycles a prototype along a street in Berlin, November 20, 2014. The wooden e-bike produced by German company Aceteam from ash wood, will be launched on the market by spring 2015 and will cost around 3,950 euro (4,950 dollars). The e-bike will be equipped with an 250W e-bike motor for a range of up to 100 kilometer (62 miles) with a rechargeable battery. (Photo by Fabrizio Bensch/Reuters)

A Guarani Indian woman jokes with her son in the village of Pyau at Jaragua district, in Sao Paulo April 27, 2015. The National Indian Foundation (FUNAI) has recognised 521 hectares of this area as indigenous territory, making it the smallest indigenous reserve in Brazil. Members of the Guarani community have now established a new village outside the demarcation and are being threatened with an eviction through a court order. (Photo by Nacho Doce/Reuters)

Fighters from Germany take up position before competing in the Medieval Combat World Championship at Malbork Castle, northern Poland, April 30, 2015. Medieval combat is a full contact sport that revives the foot based tournament fighting of medieval Europe. Countries fight in refereed matches where the objective is to get the opposing team to the floor. There are also duels with polearms, swords and shields where the number of hits landed are scored. The fighters, both male and female, wear heavy armours and weapons, mostly replicas of authentic pieces, and fight following the knights code of conduct. According to organizers, 25 nations from 6 continents are taking part in the Championships, which started on April 30 and will go on until May 3. (Photo by Kacper Pempel/Reuters)

Lebanese students dance during “The Big Dance” event in downtown Beirut, near the parliament May 9, 2015. About 1000 students from all over Lebanon gather and take part in a joint dance with the aim of encouraging people to get into dance and increase fitness levels. This initiative is part of the British Council's project, Connecting Classrooms which aims at building links between schools in the UK and Lebanon. (Photo by Aziz Taher/Reuters)

A “Maya” girl sits in an altar during the traditional celebration of “Las Mayas” on the streets in Madrid, Spain Sunday, May 10, 2015. The festivity of the Maya comes from pagan rites and dates from the medieval age, appearing in ancient documents. It takes place every year in the beginning of May and celebrates the beginning of the spring. Girls between 7 and 11 years old are chosen as “Maya” and should sit still, serious and quiet for a couple of hours in altars on the street decorated with flowers and plants and afterwards they walk to the church with their family where they attend a ceremony. (Photo by Daniel Ochoa de Olza/AP Photo)

Music student Daniele Gonzalez, (centre row, L), and Australian musician Susie Park from the Minnesota Orchestra (centre row, 2nd L), react during a rehearsal in Havana, May 15, 2015. The Minnesota Orchestra will offer two concerts in Havana and is the first major U.S. orchestra to play in Cuba since 1999. The trip cost nearly $1 million. It was underwritten by Marilyn Carlson Nelson, an heir to the Carlson hotel company fortune, and her husband Glen. The U.S. government gave special permission for a direct charter flight from Minneapolis to Havana for the event, putting 4 tons of equipment and 160 people on an Airbus 330. (Photo by Alexandre Meneghini/Reuters)

Francisco Javier Moreno (L), 35, and his wife Maria Auxiliadora Canca, 34, dressed as bandits pose for a photo with their horse as they participate in the third edition of “Ronda Romantica” (Romantic Ronda) in Ronda, southern Spain, May 16, 2015. Ronda Romantica is a cultural, historical and tourist event during the three days where thousands of people of Ronda and about fifty towns around of “Serrania de Ronda” (Ronda Mountain Ranges), dressed in traditional costumes, recreate the era of the bandits, drovers and romantic travelers in the nineteenth century. (Photo by Jon Nazca/Reuters)

A doll forms part of a sculpture as part of an exhibit titled The Sea Isn't Made for Fish at Rio de Janeiro Federal University in Rio de Janeiro, Brazil, Monday, June 1, 2015. Art students have taken advantage of a material they have in endless supply trash to create an exhibition that aims to draw attention to the fetid state of the citys Guanabara Bay, where the Olympic sailing events are to be held next year. (AP Photo/Silvia Izquierdo)