安装防爆片时应注意哪些事项？

阅读并排序 下面的短文由六个段落组成，开头和结尾已给出，其余的四个段落均是随机排列的。请根据段落之间的逻辑关系，用字母A、B、C、 D重新排列这四个段落的顺序，使短文通顺。

Samuel Clemens was born in 1835，Missouri．When he was four，his family moved to the town of Hannibal，a port on the Mississippi River，and Clemens loved to watch the big steamboats going up and down the river．He said that all the boys in his school had one ambition in life：to work on a steamboat．

小题1:In 1857, he achieved his ambition and got a job working on a steamboat. He sailed up and down the wide Mississippi River until the American Civil War began.
小题2:His father died when he was just 12 years old and Clemens then went to work for a printer to help support his family. He traveled around, and worked in many different cities.
小题3:In 1865,Clemens wrote a story about a jumping frog with his pen-name. The story and the writer became famous. After that, he wrote many books, including The Adventures of Tom Sawyer. It was published in 1876. He also gave many lectures, and became a very famous and popular man.
小题4:Clemens moved around the USA on the steamboat, and tried several jobs. He was a soldier, and a silver miner. And then he started working as a writer for a newspaper. At this time, he decided to use a pen-name for his stories, and he chose the name "Mark Twain". Samuel Clemens died in 1910. He is considered to be one of the greatest writers in American history