### Chinese: 诞生12年，比特币在2021年迎来了几个里程碑事件。
### English: Twelve years after its birth, Bitcoin met several milestones events in 2021.
### Errors: There is a major error of problems with grammar, other than orthography at "met several milestones events". There is a minor error of incorrect translation has stylistic problems at "Twelve years after its birth".

### Improved English: After coming into being 12 years ago, bitcoins ushered in several milestone events in 2021.