题目

 —I have ______  in learning English and I’m so worried. Could you help me with it? —Sure, I’d love to. A. joy         B. interest              C. trouble                   D. fun 答案：C等腰三角形的一个内角是50°，则它的顶角是 [　　] A．50°B．80°C．50°或80°D．不确定