void Main()
{
    var list=new List<model>
    {
        new model{ a=1, b=1.1F,c=1.8F},
        new model{ a=2, b=2.2F,c=1.4F},
        new model{ a=3, b=3.1F,c=1.6F},
        new model{ a=5, b=4.1F,c=1.5F},
        new model{ a=7, b=5.1F,c=1.3F},
        new model{ a=9, b=7.1F,c=1.7F},
        new model{ a=4, b=8.1F,c=1.9F},
        new model{ a=11, b=11.1F,c=1.66F},
        new model{ a=6, b=12.1F,c=1.22F}
    };
    float[] arr=new float[]{1F,1.2F,1.3F,1.4F,1.5F,1.6F,1.7F,2.2F,3.3F,4.4F,5.5F,6.6F,7.7F};
     var query=from a in arr.Select((a,b)=>new{index=b,value=a})
               join l in list
               on a.index equals l.a
               where a.value>=l.b && a.value<l.c
               select l;
    Console.WriteLine("a\tb\tc");
    query.ToList().ForEach(q=>Console.WriteLine("{0}\t{1}\t{2}",q.a,q.b,q.c));
    /*
    a    b    c
    1    1.1    1.8
    */
}
public class model
{
 public int a{get;set;}
 public float b{get;set;}
 public float c{get;set;}
}

------解决方案--------------------
探讨



------解决方案--------------------
C# code

     var s = from m in list
             where (arr[m.a] >= m.b) && (arr[m.a] <= m.c)
             select m;