题目

—Would you like to have a picnic with me this Sunday? —I’d love to. But I _______ play soccer against Class Three. A. am going             B. am going to      C. am                     D. going to 答案：B如果数据x1，x2，…，xn的平均数为4，则3x1+5，3x2+5，…，3xn+5的平均数是________．