Complex sentence: At the same time, the Pheu Thai Party members said they will dress in black for six days in mourning for the six judges who resolved to invalidate the election, while medical officers in Chiang Mai Province joined the party in wearing black.
Split into simpler sentences: At the same time, the Pheu Thai Party members said they will dress in black for six days in mourning for the six judges who resolved to invalidate the election. The medical officers in Chiang Mai Province joined the party in wearing black.