题目

设有一个直线回归方程为，则变量增加一个单位时   （ ） 平均增加个单位            B．平均增加个单位                    C．平均减少个单位            D．平均减少个单位 答案：C阅读短文并判断，用T/F表示。 Today is the sixth of May. It is Nancy’s birthday. She is eleven years old. There is a birthday party in the evening in her home. Many friends come. They all have a lot of fun at the party. Helen is listening to music. Yang Ling is playing the piano. Wang Bing and Mike are playing computer games. Now, it is time for the birthday cake. All the children sing “Happy Birthday” together for Nancy. Then, Nancy makes a wish, blows out the candles and cuts the cake. Everyone enjoys the party very much.【1】Nancy’s birthday is on the sixth of March. （________）【2】The birthday party is in the morning. （________）【3】Five children come to the party. （________）【4】There are eleven candles on the birthday cake. （________）【5】Nancy makes a wish before blowing out the candles. （________）