"现有的经济特区很好地执行了改革开放试验区的功能。"这句话翻译成英语应该怎么翻译?

The existing special economic zones have well executed their function as the experimentation areas for the reform and opening-up of China.

as 改为of

The functions of reform and opening-up experimental area have been well implemented in the present special economic zones.

The existing Special Economic Zones have performed their function well as the testing ground for China's reforming and opening-up.

perform/serve...function
testing ground