短文阅读
More than 95 percent of people in the world have phones today, according to the United Nations. People use phones to make phone calls and send ____ (信息)to communicate with others. Now we hardly write letters. But a TV show, Letters Alive, is bringing back this old ____(习惯).
Letters Alive gets its idea from a UK program with a ____ (相似的) name. They have something in common. The shows both ____ (邀请) famous actors and actresses, but there are no funny jokes or different competitions.____ (代替), it is just one person reading a letter. Since it has been on in____ (十二月) , Letters Alive has been widely praised.
The letters were written by people from different times in history. For example, once they read a letter written by famous writer Xiao Hong to her brother who is ____ (年轻的) than her in 1941. The letter shows that Xiao Hong____ (想念) her brother so much and had great hopes for his future.
“Every letter opens another world for us,” said Guan Zhengwen, the ____ (导演) of the TV show. “It seems that we can experience the real lives and feelings of the writers.”
____ (不管怎么说)，many people said that it has provided a breath of fresh air to today's TV shows.
圆弧面的物体固定在水平地面上，圆弧面底端切线水平，一根两端分别用轻绳系有质量为m1、m2的小球跨过其顶点上的小滑轮。当它们处于平衡状态时，连结m2小球的轻绳与水平线的夹角为600，不计一切摩擦，两小球可视为质点。两小球的质量之比ml : m2等于（ ）
