2021英文为：two thousand and twenty-one。
例句：
1.For example, the United Arab Emirates has endorsed an ambitious target to draw 24% of its primary energy consumption from renewable sources by 2021.
例如，阿联酋已经批准了一个雄心勃勃的目标，即到2021年实现24%的主要能源消耗提取自可再生能源的目标。
2.If Sandakan wins and extends it to the North and South Circular roads in 2021 as he intends, it is sure to spark intense opposition from the far larger number of motorists who will then be affected.
如果山达干获胜，并按照他的计划在2021年将其扩展到南北环形道路，这肯定会引发更多的驾车者的强烈反对，他们将受到影响。
3.If Sadiq Khan wins and extends it to the North and South Circular roads in 2021 as he intends, it is sure to spark intense opposition from the far larger number of motorists who will then be affected.
如果萨迪克·汗获胜，并按照他的计划，在2021年将其推广到南北环线道路，这肯定会引发更多驾车者的强烈反对，因为他们将受到影响。
4.Costa Rica plans to go carbon neutral by 2021.
哥斯达黎加计划到2021年实现碳中和。
