汽车在水平路面上从静止开始做匀加速直线运动,t1末关闭发动机,做匀减速直线运动,t2末静止,其v-t图象如图所示,图中α<β,若汽车牵引力做功为W,平均功率为P;汽车加速和减速过程中克服摩擦力做功分别为W1和W2 , 平均功率分别为P1和P2 , 则 ( )
In September, 2014, Asia's biggest tennis star, Li Na retired (退役) from tennis. She made the because of the pain in her right knee, but she said, "I'm very pleased with my tennis career. I don't feel sorry or have any regrets about retiring."
Li Na was born on February 26,1982 in Wuhan, Hubei Province. She started to play tennis at the of six She is one of the greatest sports stars in. China. She the 2011 French Open, becoming the first player from China to win a Grand Slam singles title (大满贯单打头衔), and clinched the Australian Open title in January, 2014.
Li has tens of thousands of fans in China. They call her "Big Sister Na"; and "Golden Flower". After hearing the news, many people said they respected her decision and wished her the best. "We thank Li Na. She has brought many proud and shining moments to Chinese tennis."
the retirement, Li wants to enjoy the family life. She wants to open a tennis college to help build up the base for Chinese tennis.
小明在“研究弹簧的伸长与外力的关系”的实验中,利用如图所示的装置,在弹簧下端分别挂不同个数的钩码(质量相等),使弹簧受到竖直向下的拉力,同时在刻度尺上读出每次弹簧下端指针的位置,将数据记录于下表。
| 所受拉力F/N | 0 | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 | 4.0 |
| 指针位置x/cm | 2.5 | 3.0 | 3.5 | 4.0 | 4.5 | 5.0 | 5.5 | 5.8 | 5. 8 |
| 弹簧的伸长x1/cm | 0 | 0.5 | 1 | 1.5 | 2 | 3 | 3.3 | 3.3 |

将表格中数据补充完整。
分析表中实验数据,得到的结论是: 。
(3) 用题目中的弹簧制成弹簧测力计,其量程是 N 。
吃了
,( )?
提出一个数学问题并解答。
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①“一国两制”是适合我国国情的政治协商制度
②民族区域自治制度符合全国各族人民的共同利益
③祖国的繁荣昌盛是澳门特区持续发展的坚实后盾
④“一国两制”是澳门保持繁荣稳定的最佳制度
在
中存在零点,用二分法求零点时,若要求精确度为0.01,则运算次数至多为7次
B . 已知函数
(
且
)在
上是减函数,则实数
的取值范围是
C . 在同一平面直角坐标系中,函数
与
的图象关于直线
对称
D . 若
,则
的值为1
—One yuan.
、
互为相反数,
、
互为倒数,且
,则
的值为.
( 1 ) Bob is heavier than Peter.
( 2 ) I cleaned my room yesterday afternoon.
( 3 ) Jenny had a cold last Monday.
( 4 ) Tim rode a horse last summer holiday.
( 5 ) There is a new gym in our school.
A.
B.
C. 
D.Peter
Bob E. 
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参加 人参 参差不齐 参谋
