已知直线 $l:y=-x+3$ 与椭圆 $C:m{x}^2+n{y}^2=1(n>m>0)$ 有且只有一个公共点 $P\left(2,1\right)$ .

建国初期，地主土地所以制被废除，三亿多无地或少地的农民获的了土地，这得益于（    ）

有一个转盘（如图所示），被分成6个相等的扇形，颜色分为红、绿、黄三种，指针的位置固定，转动转盘后任其自由停止，其中的某个扇形会恰好停在指针所指的位置（指针指向两个扇形的交线时，重新转动）．下列事件：①指针指向红色；②指针指向绿色；③指针指向黄色；④指针不指向黄色．估计各事件的可能性大小，完成下列问题：

（1）可能性最大和最小的事件分别是哪个？（填写序号）

（2）将这些事件的序号按发生的可能性从小到大的顺序排列：              ．

阅读理解
    American country music is also known as(被称为)country Western music．It has a very long history．It comes from the folk songs of immigrants(移民)from Britain．
    Country music uses simple music and words to express everyday feelings such as loneliness，love，and sadness．That is to say，country music describes life．It talks about friends and enemies，trucks and roads，farms and crops．People in many parts of the world like country music，because everyone can understand what the music is about．
    Country Western music became popular first among cowboys(牛仔)in the American West courttryside．Cowboys had to take care of cows day and night．When they were alone with the cows，they often sang beautiful and peaceful songs to calm the animals and to overcome their own fear．They were not well—educated and so they sang about their daily life in very simpie words．They played guitars，violins，and other instruments．  In the south of America，many people added instruments from their homes，like bottles and spoons．  When cowboys visited their friends and families on holidays like Thanksgiving，they usually sang and played country Western music．
    In recent years，many musicians have made country Western music a little different from the one in the past．These changes make the songs sound even better．Today singers such as Garth Brooks， Reba McEntire，Emmylou Harris，Lyle Lovett，Eddie Rabbitt，LeAnn Rimes，Randy Travis，and a group called Alabama are singing and playing in different styles．They have brought country Western music more and more fans from all over the world．

人的心肌细胞明显比腹肌细胞多的细胞器是