题目

—So many people like to watch The Voice of China.— wonderful it is! I like it very much. A . How B .What C .What an D . How a 答案：A已知函数f(x)=lg，若f(A)=B，则f(－A)等于（　　 ） A.B　　    B.－B　　   C.　　   D.－