A、It is a new kind of cell phone battery. B、It is a kind of material which uses body heat to charge a battery. C、It is a device

Charging your cell phone may soon require only two items: a simple piece of fabric and your body. Researchers have developed a “Power Felt” that uses thermoelectric technology to charge devices such as cell phones. Working in conjunction with outside temperatures, the material is capable of turning body heat into an electrical current to keep personal electronic devices up and running. Currently, the material only produces 140 nanowatts of power, which is about “a millionth of the power your iPhone uses when it’s idle,” but scientists are doing further research and hoping to largely improve the quality of the material. Eventually, the research team hopes to market a phone-sized fabric swatch for just ＄1. It is said that charging a phone with the material is easy: just attach the fabric near the battery and hold the device in your hand. With further improvements, the device might come in handy for distance runners who need to charge their digital music players while they’re out on the town. It’s pretty cool to make a jacket with a completely thermoelectric inside liner that gathers warmth from body heat, while the exterior remains cold from the outside temperature, and it’s definitely within reach. In addition to the obvious convenience factor, scientists said the material might be useful in urgent situations. You could imagine it in an emergency kit, wrapped around a flashlight, powering a weather radio... Questions 23 to 25 are based on the passage you have just heard.
23. What is a “Power Felt”?
24. What can we learn about the “Power Felt” currently?
25. What can be learned about the future of the “Power Felt”?