Answer:
The natural satelite Europa and the planet Mars are the two rock systems more likely to earth on their conditions all about solar system. Europa has a huge liquid water ocean and temperature is pretty similar to earth, Mars also has water but it's in solid state and the temperature also is good, not during the nights but still is good enough.
That is an opinion. Opinion is not fact, although it can be based upon fact.
A. Base , salt , water,acid
Solar cells can be classified into first, second and third generation cells. The first generation cells—also called conventional, traditional or wafer-based cells—are made of crystalline silicon, the commercially predominant PV technology, that includes materials such as polysilicon and monocrystalline silicon.