Here are 5 key takeaways from the article:

1. **China's exports growth stronger than expected**: China's exports rose by 8.7% year-on-year in August, beating the expected 7.04% increase.
2. **Imports growth slows down**: Import growth slowed down to 0.5% in August, a decrease from 7.2% in July, indicating weaker domestic demand.
3. **Trade surplus increases**: The trade surplus reached US$91.02 billion in August, up from US$84.65 billion in July, as exports outpaced imports.
4. **Regional export growth varies**: Exports to specific regions showed varying growth rates: 8.78% to ASEAN, 10.37% to Russia, and 13.39% to the EU.
5. **Economists uncertain about sustainability of export growth**: Despite strong export numbers, economists have mixed views on whether China's export momentum can last amid global economic uncertainties and rising trade tensions.

Overall, the article suggests that while China's exports are performing well, there are concerns about their sustainability due to external factors affecting the global economy.