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．

如图，在Rt△ABC中，∠C=90°，以顶点A为圆心，适当长为半径画弧，分别交AC，AB于点M，N，再分别以点M，N为圆心，大于 $\frac{1}{2}$ MN的长为半径画弧，两弧交于点P，作射线AP交边BC于点D，若CD=4，AB=15，则△ABD的面积是（   ）

为了判断一个小铁球是不是空心的，小明同学用天平、量筒和水测得如下数据：

铁球的质量m/g	量筒内水的体积V水/ml	量筒内水和铁球的总体积V总/ml
790	200	350

世界上面积最大的岛屿是（　　）

如图是硫原子的结构示意图，请回答：

（1）硫原子的质子数是____ ；

（2）硫原子核外有____ 个电子层，最外层上有　____ 个电子；在化学反应中相对较易____（填“得到”或“失去”）电子．