资料题：According to the passage, a home computer can best be described as（　）。

Nothing lives forever.Is that right? Wrong.It seems hard to believe that there are some animals that do not die.They are very simple creatures, too small to be seen without the help of a microscope.While most animals, including human beings, have billions of cells in their bodies.These little defiers have only one.Each cell lives for a certain length of time, and then it splits to form two new animals.The adult animal turns itself into two babies.All of the new cells finally divide, but none die unless they are killed by accidents or by diseases.There are other cell that avoid being old Cells from old mice have been moved into young mice over and over again, each time the body they are in wears out.In their new bodies the old cells seem to begin life over again.They divide and grow just like young cells.Is there any way to discover the secret of these young cells and apply it to human beings? Not yet.But scientists.are still searching and they may be closer than ever to finding an answer.Of course, some ways to increase our chances of living longer, like good food and exercise, have been known for years.Progress against killer diseases has already raised the human life to more than seventy years, compared with less than fifty years at the turn of the century.Now scientists are studying other ways to fight against death.They will never give up their efforts until they wintheir final -success.