Swimming is very popular in summer. People like swimming in summer because water  m____ people feel cool. If you like swimming and swim in a wrong place, it may not be safe(安全的). Last summer, more than ten people died  w____  they were  e____  themselves in the water, and  m____ of them were students. But some people are  s____  not careful in swimming. They often think they swim so well that n____  can happen to them in water. Summer is here again , if you go swimming in summer, don't forget that better swimmers have died in  w____ . They d____  only because they were not  c____ , not because they could not swim. So don't get into water when you go swimming  y____ , go with your teachers or your parents. If there are “No  S____ ” sign, don't get into water, either. If you  r____  these, swimming will be safer.