对于简单机械来说，提升重物时，克服___________所做的功为有用功。实际拉力做的功为________。那么机械效率的计算公式可写作η=_____________。
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据等高线地形图（如图），回答问题．
（1）写出图中字母所代表地形部位名称
A______B______
C______D______E______．
（2）图中小河F的流向是______．
（3）山顶甲在山顶乙的______方向．
（4）甲、乙两山顶的相对高度是______．
不宜与昔鲁卡因合用的抗菌药物
A．喹诺酮类药物
B．头孢菌素
C．磺胺药
D．克林霉素
E．甲氧苄啶
| 完形填空。 | ||||
| Many people of my generation say that there is no hope for the future because of the way that young people behave today. Their first argument is that when we were 1 we used to look after the older people in our community and help them. They also say that young people today don't care about anything or anyone. 2 , I think the reason why we looked after older people was that we had no 3 . People had to live with their parents and grandparents because they had no money. Young people today earn more and have more freedom to live where they want. 4 this, I think that they are still interested in older people. For example, young people often 5 to help me when I get on and off the bus with heavy shopping. Their second argument is that in our day we didn't 6 to be given jobs-and that young people now don't look for jobs, but just complain about unemployment. On the other hand, things were easier in the past and it was always easy to get a job 7 you had friends and contacts. It is really harder today. Young people complain about unemployment and I think they have 8 reason to complain. In conclusion I think there is 9 for the future. This generation, like generations before them, has new 10 as well as old problems. If they learn from our mistakes the world will be a better place in future. | ||||
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固定电话用户因移机或改号变更电话号码，为不影响对外联系，用户启用新号（）后，1个月内，凭有效证件到各营业厅办理在原电话号码上播放语音通知的业务。
某人因有机磷农药中毒，致使神经纤维末梢释放的乙酰胆碱不能失活而作用加强。患者不会出现的症状是
A．消化道运动增强，腹痛，腹泻
B．瞳孔缩小，视力模糊
C．肌肉震颤，抽搐
D．皮肤干燥，无汗
E．支气管平滑肌收缩，呼吸困难