题目

a few, vacation, boring, more than, visit, camera, famous,interesting, remember, thought,Second, forget I'm going to visit Xi'an for my【1】this summer. I'll fly there on July 28th and stay there until August.First, I want to【2】the old city wall. There were many old city walls in Xi'an in the past. But now there are only【3】walls left. They are【4】700 years old. Lots of them were pulled down(推倒)in the 1960s. People【5】they were not useful and they made the traffic heavy and the streets crowded (拥挤). Some of them were even dangerous. Today, our country is trying to build 在“验证机械能守恒定律”的实验中，打点计时器接在电压为E，频率为f的交流电源上，在实验中打下一条理想纸带，如图所示，选取纸带上打出的连续5个点A、B、C、D、E，测出A点距起始点的距离为，点AC间的距离为，点CE间的距离为，已知重锤的质量为m，当地的重力加速度为g，则           （1）.起始点到打下C点的过程中，重锤重力势能的减少量为＝         ，重锤动能的增加量为＝          .（2）根据题中提供的条件，可求出重锤实际下落的加速度a=         ,它和当地的重力速度g进行比较，则a       g（填“大于”、“等于”或“小于”）.