Fingernails grow on fingers, which plays a very good protective role. People write, take things, work and play games by hand every day. Without the support and protection of nails, won't their fingers grind and bleed? Look, how useful nails are. Therefore, children must pay attention to protecting their nails. Of course, fingernails should not be left too long. There are many bacteria and eggs in long nails, which are likely to infect food and make people sick.