题目

如图，点，，均在⊙上，当时，的度数是（ ）A. B. C. D. 答案：【答案】A【解析】先利用等腰三角形的性质和三角形内角和计算出的度数，然后根据圆周角定理可得到的度数．，，，．故选A．- There is something wrong with your bike, ___? -Yes. I'll have it _   tomorrow. A．isn’t it; mendB．isn’t there: mendedC．isn't it; mendedD．isn't there; mend