Mark was walking home from school one day when he noticed a boy ahead of him had dropped all of the books he was carrying. Mark helped the boy pick them up. 16 they were going the same way, he
已知（1）H2（g）+1/2O2（g）===H2O（g） △H1=a kJ·mol-1 （2）2H2（g）+O2（g）===2H2O（g） △H2=b kJ·mol-1 （3）H2（g）+1/2O2（g）===H2O（l） △H3=c kJ·mol-1 （4
如图所示，质量均为m的A、B两球之间系着一条轻弹簧放在光滑水平面上，A球靠紧墙壁，现用力F将B球向左推压弹簧，平衡后，突然将力F撤去的瞬间，则
—Did you tell her the bad news? —Yes，but I'd rather ________. A．didn't B．not C．not have D．hadn't
阅读下面的文字，完成后面题。 “宫斗剧”的文化本质 顾名思义，“宫斗剧”中几乎所有的故事都发生在与世隔绝的后宫中，“斗”是其核心情节和叙
根据要求作文。 在你的成长中，总有那样一件事让你终生难忘，总有那么一段经历让你刻骨铭心……请以“从那以后”为题，写一篇记叙文。 要求：思
