阅读填空。根据下面短文内容，在短文的空格处填上一个恰当的词。使短文完整、通顺。
Swimming is very popular in summer. People like swimming in summer, because water _____ people feel cool. But if you like swimming and swim in a wrong place, it may not be ______. Last summer, more than ten people died when they were enjoying ______ in the water, and most of ____were students. But some people are still not careful in swimming. They often think they swim so well____ nothing can happen to them in water. Today is July 10^th, summer      coming soon. if you want _____enjoy swimming in summer, don’t forget that better swimmers have died in water. They died only because they were not careful, not because they could not swim. So don’t get into water when you go swimming alone, go       ______ your teachers or your parents. If there      “No Swimming” signs near the river or lake, you         get into water. If you remember these rules, swimming will be safer.