阅读理解。 One of the best-known American writers is Samuel Clemens, whose pen name is Mark Twain. Born in 1835, Clemens grew up in the Mississippi River town of Hannibal, Missouri. As did many other young people of his day, Clemens dreamed of traveling on riverboats and of someday becoming a riverboat pilot. He used his memories (记忆) of the life of a river town in his two most famous books, Huckleberry Finn and Tom Sawyer. As a young man, Clemens held many jobs. He was a printer (印刷工), a gold miner (矿工) and a riverboat pilot. During his pilot days, he used the name Mark Twain. This was a term used on the river to mean that the water measured (测量) 2 fathoms (), or 4 meters (nearly 12 feet), which was deep enough for safe passage. Finally Twain became a successful writer. He traveled a great deal, writing and speaking. He became very popular both in the United States and in Europe. Twain's style of writing was simple and direct. Among the things that he wrote about were superstitious (迷信的) people and people who were really fool. He used his unusual gift for humor (幽默) to write about many things of importance. 阅读短文,然后判断正(A)误(B). ( )1. This article as a whole is about a riverboat pilot. ( )2. Mark Twain worked as a pilot all the time before he became a successful writer. ( )3. Mark Twain knew much about the Mississippi. ( )4. It is very difficult to understand Mark Twain's works. ( )5. Huckleberry Finn is a book about the life of the Mississippi River.