What will power your house in the future? According to scientists at the Massachusetts Institute of Technology (MIT) in the US, it might be artificial leaves.    Natural leaves can change sunlight and water into energy. It is known as photosynthesis . Now researchers have found a way to imitate this process.    The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip with catalysts . Similar to natural leaves, it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell, using those two materials to produce electricity, located either on top of a house or beside the house.    Though the leaf is shaped like a poker card, scientists stated that it is promising to be an inexpensive somtoe of electricity in developing countries. "One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology," said an American scientist, Docera.   An artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but too expensive and unstable for practical use. The new leaf, however, is made of cheap materials, easy to use and highly stable. In laboratory studies, Nocera showed that an artificial leaf could operate continuously for at least 45 hours.    The wonderful improvements come from Nocera's recent discovery of several powerful new, inexpensive catalysts. These catalysts make the energy transformation inside the leaf more efficient with water and sunlight. Right now, the new leaf is about 10 times more effective at carrying out photosynthesis than a natural one. Besides, the device can run in whatever water is available.      Hopefully, each home could possible have the access to the new application in the future. The purpose of this article is to   _  .
promote the new product ask people to do the research introduce a new kind of energy show the process of photosynthesis
Question: What will power your house in the future? According to scientists at the Massachusetts Institute of Technology (MIT) in the US, it might be artificial leaves.    Natural leaves can change sunlight and water into energy. It is known as photosynthesis . Now researchers have found a way to imitate this process.    The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip with catalysts . Similar to natural leaves, it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell, using those two materials to produce electricity, located either on top of a house or beside the house.    Though the leaf is shaped like a poker card, scientists stated that it is promising to be an inexpensive somtoe of electricity in developing countries. "One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology," said an American scientist, Docera.   An artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but too expensive and unstable for practical use. The new leaf, however, is made of cheap materials, easy to use and highly stable. In laboratory studies, Nocera showed that an artificial leaf could operate continuously for at least 45 hours.    The wonderful improvements come from Nocera's recent discovery of several powerful new, inexpensive catalysts. These catalysts make the energy transformation inside the leaf more efficient with water and sunlight. Right now, the new leaf is about 10 times more effective at carrying out photosynthesis than a natural one. Besides, the device can run in whatever water is available.      Hopefully, each home could possible have the access to the new application in the future. The purpose of this article is to   _  .
A. promote the new product
B. ask people to do the research
C. introduce a new kind of energy
D. show the process of photosynthesis
Answer: