题目

如图，在光滑的水平面上，一劲度系数为K的轻弹簧左端固定在墙上，右端与一质量为M的物块拴接，并处于静止状态，某时刻给M一个水平向左的初速度，经过时间T，弹簧第一次被压缩得最短，最大压缩量为X，则下列关系式正确的是（       ） A  t=mv0       B   kx2=mv02             C  =        D 以上关系式均不正确词汇运用。（10分） 1.Great ________(change) have taken place in Yangzhou these years. 2.Jim is very ________(care), but he didn’t make many mistakes. 3.Every weekend, my mum with I often goes to buy some ________(day) things. 4.Who is the _______(busy) in your family? 5.Millie is clever. She can always answer the questions__________ (correct). 6.The woman is ______ 50, but she looks very young. (已经) 7. It’s ___________(有意义的) for us to help others. 8.Yesterday, I _______(收到) a letter from my friend. 9.The _____ (花费)from Yangzhou to Taizhou is about 18 yuan. 10.All the boys are good _______(登山者).