关于五种地形的说法，正确的是（   ）

世界着名的“低地国”是                      (     )

完型填空
      Books are our greatest friends. They 1us stories of every country in the world. They give us all kinds of 2 . Life is short. One can not know and see 3 in the world. 4 the help of books, one is able to know what happened thousands of years ago and 5 is happening in every part of the world now. Books give us not only knowledge 6  pleasure. Reading good books is the best way of7    our free time. And many beautiful stories for children are 8and full of wisdom(智慧).
    All the great men 9 books. Knowledge from books helps them to succeed, because books are the source(源泉)of knowledge and knowledge is the source of  10 .