要规范工程建设参与各方的建设行为，就要建立有效的约束机制，其根本目的是( )。A．

     Swimming is very popular in summer. People like    1    because water    2    them feel cool. But if
you   3    swimming in a wrong place, it may not be safe (安全的). Last summer, more than twenty
people died while (当……的时候) they were having fun in water. Most of them were students. However,
some people are still not careful (小心的) in swimming. They often think they swim so well. Summer 
   4    again. If you want    5    swimming in summer,   6     that better swimmers have died in water.
They died only because they    7    not careful, not because they    8    not swim. So don't get into water
 when you go swimming by yourself. If there is "No Swimming" sign, don't get into it, either. If you
remember these, swimming will be safer.
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