题目

设α∈，则使f(x)＝xα为奇函数，且在(0，＋∞)上单调递减的α的值的个数是( ) A．1                                    B．2 C．3                                    D．4 答案：A句型转换 He would go to America by plane.(改为同义句) He would________ ________America.