题目

小明同学买了一个玩具直升机，通过阅读说明书发现该直升机加速度可以达到5m/s2，但该直升机离开遥控器一定距离后就会失去信号导致电动机自动关闭，需要重启遥控器才能重新控制直升机，某次操作中小明将直升机放于草坪上，然后通过遥控器启动直升机并使直升机以最大的加速度竖直向上起飞，通过遥控器显示屏发现直升机4s后超出了控制范围，不计空气阻力，g=10m/s2求：(1)直升机所能到达的最大高度(2)此次操作中直升机在空中一共运动了多长时 　　By choosing to let go of the past, we can sweep out all the ashes that weigh us down and affect every aspect of our health, our relationships, and our peace of mind． 　　My friend Jean was divorced after a thirty-year marriage that produced three daughters, one son and eight grandchildren．Because she had actually raised them single-handedly, Jean was hurt and angry that the children didn’t take her part after the divorce．For months she refused to attend any family celebration to which her former husband Jim was also invited．When I reasoned that her children’s understanding of the relationship with and between the parents was probably altogether different from hers, she stuck to the belief that she was right． 　　One day Jean called in tears．“Saturday is my granddaughter’s birthday, and I really want to be with her, but I can’t bring myself to face my former husband.”“Jim isn’t the problem,”I said gently,“its false pride．Instead of holding on to the painful past, which is over and done, let the feelings go and get on with your life．You’re depriving yourself of the joy of sharing in these important occasions, while Jim feels free to experience them．Tell me, would you rather be right, or be happy?” 　　That must have done the trick because when Saturday arrived, Jean appeared at her daughter’s home carrying her famous chocolate-chip cookies and a beautiful birthday cake． 　　How great it feels to let go!How energizing!And the more we practice the art of letting go of all negativity, the better able we become to devote our thoughts, our time, and our energy to living joyfully in the present, what ever age we happen to be． (1) It can be inferred that ________． [　　] A． Jim did very little to bring up the children during their marriage． B． the writer thought Jean and Jim shouldn’t have divorced C． the children were on their father’s side and didn’t invite Jean to any family celebration D． Jean had been too tough on Jim before they were divorced (2) The underlined phrase“depriving yourself of”is closest in meaning to“________”． [　　] A． persuading yourself to get B． taking away from yourself C． taking false pride of yourself D． talking yourself into showing (3) In the writer’s opinion, ________． [　　] A． Jean and Jim should be remarried B． a broken family could live together in peace C． to be happy is more meaningful than to be right D． everyone should look into the future (4) Which is the best title? [　　] A． The Trick Is Done Successfully B． The Younger Generation Is More Open-minded C． Follow the Advice of Others in Time of Trouble D． It Is Time to Let Go