题目

While walking around the Xixi National Wetland Park, I found there were tens of thousands of people, young and old, ______ for the flower festival. Beautiful indeed! A. dressed up    B. come up    C. picked up    D. turned up 答案：C 解析: 略有一科学家说：“给我一个支点，我将撬动整个地球。”这个科学家的成就是 ①发现杠杆定律           ②发现浮力定律           ③发明螺旋式水车 [     ]A．① B．② C．①② D．①②③