齿侧间隙过大，则会造成齿轮换向（）大，容易产生冲击和振动。

用方框中所给单词的适当形式填空，使短文正确，通顺。（每词限用一次）

large  population  five  live  other  find  short  crowed   and   become

The population in China
China has the  95 population in the world, and about one  96 of the people in the world live in China. Because of the large   97   , there is less  98 space for each family. And it’s difficult for lots of people   99   jobs. The large population also causes many  100  difficulties for the whole nation .For example, we’re  101 of energy and water. Most cities are   102  than before,  103  the traffic is much heavier .The large population  104  a serious problem.