I. 1. Without doubt

   2. by accident

   3. divided into

   4. remains

   5. All of a sudden

   6. look up to

II. 1. was invented

    2. was translated

    3. was given; was given to

    4. was heard

    5. was put

III. 1. come up with

     2. The number of

     3. not only; also

     4. have a point

     5. encourages; to work hard

     6. are used for

IV. One possible version:

This is an ancient China seismometer. It was invented by Zhang Heng who was born in 78 A.D. in Han Dynasty in ancient China. It was made of copper and other metals. The seismometer was used to forecast the earthquake. It was the first machine to forecast earthquakes in the world, which made great contributions to the study of the disasters. Zhang Heng was so great a man that he will be remembered not only by the Chinese people but also by the world forever.