reduce to a shadow

例句：

1. 1.The population of the city has been reduced by 20% in the past five years.
   过去五年里，这个城市的人口减少了20%。
2. 2. The cost of living has decreased due to economic growth.
   由于经济增长，生活成本已经下降。
3. 3.The company is reducing its workforce to save money.
   公司正在减少员工人数以节省开支。