题型:判断题 Read and answer.1. Do you have a cold today? 2. Are you happy now? 3. How tall are you? 4. How heavy are you? 查看答案
题型:判断题 如图所示,杂技演员从地面上的A点开始骑摩托车沿竖直圆形轨道做特技表演.已知人与车的总质量不变,车的速率恒定,若选定地面为零势能参考平面,则摩托车通过C点时( )A.机械能与A点相等B.动能比在A点大C.机械能比在A点大D.重力势能比在A点大 查看答案