What were 5 great acheivements of the Sui?

Gabbie, I just found some achievements made during the Sui Dynasty.
1. Emperor Wendi established an advanced political system called three-tier system and six ministries. This political system was adpoted widely in later dynasties.
2. Imperial examination system was established to select officials. It was firstly applied in 605 AD and ended in 1905 of the Qing Dynasty.
3. Grand Canal. Many people criticized that Emperor Yangdi spent too much money and deployed many civilians to build the Grand Canal just to meet his own personal desires. It's true. However, this canal also strengthened the communication between northern and southern China.