Ⅰ、1、protect
    2、conditions
    3、achieve
    4、succeed
    5、include
    6、nature
    7、force
    8、square
    9、population
    10、meters
    Ⅱ、1、higher
    2、the biggest
    3、the deepest
    4、the longest
    5、countries
    6、the most famous
    7、the most popular
    8、southwestern
    9、themselves
    10、trying
    Ⅲ、1、most dangerous sport
    2、One of the most popular places
    3、The first people to reach the top
    4、risk their lives
    5、in the face of difficulties
    6、never give up
    7、The force of nature
    8、As you can see
    9、8850 kilometers long
    10、part of
    11、Almost as long as
    Ⅳ、1、what
    2、how high
    3、deeper than any other
    4、as long as
    Ⅴ、1 - 5 C E D B A