German summers are getting hotter and hotter — but the Environmental Agency in the small city of Giessen, in the state of Hesse, has come up with an innovative tool for helping residents keep cool: a special city map! Copyright: Deutsche Presse Agentur [The German Press Agency]

Humans and animals often form their own special kinds of bonds. Here, you’ll learn about people who developed friendships with a crow, a shark, a goose, and more!

Can you imagine having a raccoon as a pet, a tiger as a playmate, or a crocodile as a friend for life? What about a reunion with a lioness? Watch this video for more accounts of wild animals who have formed bonds with people.

We imagine to sharks to be big, scary, and full of serrated teeth – but some species are actually harmless! Learn more about the friendly giants in this video.

Dolphins, sea lions, and beluga whales – which marine mammals are the friendliest?

More friendly marine animals! Here, we meet the charismatic mola mola, the cute but often aggressive sea otter, and the pack-oriented orca.

What are the top three friendliest sea creatures? We won’t give the answer away, but you can find out more in this video!

Air travel has been the focus of much scrutiny lately due to its devastating effects on the environment. How will the aircraft of the future address this problem?

What sounds like a distant vision of the future is already possible today – at least when it comes to technology. Will quadcopters and "soulless" unmanned aircraft soon be transporting hundreds of passengers over long distances?

Freaked out by the idea of a pilotless plane? How about one without any moving parts at all – no turbines, no propellers? The next generation of aircraft could involve ion propulsion, which allows planes to take off and land anywhere – all without making a sound.

Julia and Marie have recently moved to Berlin and are waiting for their friend Brigitta to arrive for a visit.

After picking her up from the train station, the two roommates are very excited to show Brigitta their apartment. She is impressed, but also very tired from traveling.

After a good night's sleep and a delicious breakfast, Brigitta's friends want to take her out to see their neighborhood. They hope that they can even convince her to move there.

Brigitta finds out that her friends are having some trouble getting along as roommates and communicating about their expectations.

When Marie comes home and has a few complaints about living with Julia, it's clear to Brigitta that the two of them need to talk.