题目

—That actor often joins in dfferent activities in Beijing. Do you know        ? —For 5 years.A. how soon he will come back            B.how long he has stayed thereC. how long has he stayed there        C. how often does he go there 答案：B下列说法正确的是（　　）A．过一点有且只有一条直线与已知直线平行B．相等的两个角一定是对顶角C．将一根细木条固定在墙上，只需要一根钉子D．同角的余角相等