请问这句话有语法上活时态上的错误吗?

请问这句话有语法上活时态上的错误吗?
At the ceremony of your school's 100th anniversary,we should also celebrate the achievement that china has gained in the past 20 years.200 million persons have get rid of poverty; the yearly per capita economic growth rate has reached 7 percent to 8 percent; average life expectancy has heightened 10 years.