题目

—I want to know if Maria us in the fashion show tonight. —I believe if she her homework, she will join us. A . joins; finishes B . will join; finishes C . joins; will finish D . will join; will finish 答案：B将函数y=sin（x-θ）的图象F向右平移π3个单位长度得到图象F′，若F′的一条对称轴是直线x=π4，则θ的值是 ．