You ________ the exam but you failed this time． A．were supposed to pass B．supposed to pass C．were supposed passing
抛物线的对称轴是直线（ ） A． B． C． D．
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一起重机的钢绳由静止开始匀加速提起质量为m的重物，当重物的速度为v1时，起重机的有用功率达到最大值P，以后起重机保持该功率不变，继续提升重
“为雪心头恨，而今作楚囚。被拘三十二，无一怕杀头。痛殴卖国贼，火烧赵家楼。锄奸不惜死，来把中国救。”材料中所反映历史事件的直接原因是
Mr. Smith has two cats. One is big and the other is small. He likes them very much. One day his good friend Mr. White comes to see him. He is very surprised(惊奇的).He finds there are two holes(洞
如图所示，在水平力F的作用下，重为G的物体保持沿竖直墙壁匀速下滑，物体与墙之间的动摩擦因数为μ，物体所受摩擦力大小为A．μF B．μ（F+G）
She wasquiet p______ about the amount of money.
