题目

---- ______ you ______ to see that exhibition yet?  ---- Yes, I ______ it last Sunday. A. Did, go, saw  B. Have, gone, saw   C. Did, go, seen  D. Have, gone, went    答案：D一个凸11边形由若干个边长为1的正方形或正三角形无重叠、无间隙地拼成，求此凸11边形各个内角大小．