[单选题]设R、S、T是集合A={a，b，c}上的关系，定义如下：R={<a,b>}S={<b,b>,<b,c>}T={<b,c>}计算R◦（S U T）=（ ）。
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2023-11-01 15:11:12|
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[单选题]设R、S、T是集合A={a，b，c}上的关系，定义如下：R={<a,b>}S={<b,b>,<b,c>}T={<b,c>}计算R◦（S U T）=（ ）。
A.{ < a , c > }
B.{<a,b>,<a,c>}
C.{ < a , b > , < b ,b > , < b , c > }
D.{ < a , b > , < a , c > , < b , b > , < b , c > }
A.{ < a , c > }
B.{<a,b>,<a,c>}
C.{ < a , b > , < b ,b > , < b , c > }
D.{ < a , b > , < a , c > , < b , b > , < b , c > }
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