There could be a few reasons for an unlit helicopter flying over Lankwitz at night. It's possible that the helicopter is conducting a military or law enforcement operation that requires stealth, such as surveillance or a rescue mission. Another possibility is that the helicopter is experiencing a technical issue with its lights, causing them to malfunction. Additionally, the helicopter could be participating in a training exercise that involves flying without lights to simulate nighttime combat scenarios. **

A paragliding tandem pilot is an experienced and certified individual who is responsible for flying a tandem paraglider with a passenger. They are trained to safely navigate the paraglider through the air, control its speed and direction, and ensure a smooth and enjoyable flight for the passenger. Tandem pilots must have a deep understanding of paragliding techniques, weather conditions, and safety protocols to provide a memorable and secure experience for their passengers. **

No, paragliding does not work solely through wind energy. While wind plays a crucial role in paragliding by providing lift and allowing the glider to stay airborne, the sport also relies on the pilot's skill in controlling the glider and using thermals (rising columns of warm air) to gain altitude. Additionally, the pilot can use the glider's speed and the shape of the terrain to maintain flight, meaning that paragliding is not solely dependent on wind energy. **

"Foot" is the singular form, while "feet" is the plural form. For example, "I hurt my foot" refers to one foot, while "I hurt my feet" refers to more than one foot. It's important to use the correct form depending on whether you are referring to one or multiple feet. **

It is not accurate to label feet as "flat" or "normal" as there is a wide range of foot shapes and arch types that can be considered normal. Some people have lower arches, which may be referred to as "flat feet," while others have higher arches. Both types of feet can be considered normal and functional. It's important to focus on the overall health and function of the feet rather than categorizing them as flat or normal. **

Closed windows of unlit rooms often appear dark or black from the outside because light cannot pass through the window into the room. Without any light entering the room, the interior appears dark in contrast to the brighter exterior surroundings. This lack of light reflection or transmission through the window creates the perception of darkness or blackness when viewed from the outside. **

To determine if you have normal feet or flat feet, you can perform a simple test. Wet your feet and then stand on a flat surface where your footprint can be seen. If you have a normal arch, you will see a curve along the inside of your foot connecting the ball of the foot to the heel. If your footprint shows the entire sole of your foot with little to no curve, you likely have flat feet. It is recommended to consult with a healthcare professional for a proper diagnosis and treatment if needed. **

I'm sorry, but as a language model AI, I do not have the ability to physically see or assess your feet. To determine if you have wide or narrow feet, you can try measuring your feet or visiting a shoe store for a professional fitting. Wide feet typically require shoes with a wider width size, while narrow feet require shoes with a narrower width size. **