[InKunming--Sister Cities]  An actor from Vietnam performs a musical instrument during the 15th China-ASEAN (Association of Southeast Asian Nations) Expo held at the Nanning International Convention and Exhibition Center in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, Sept. 12, 2018. The expo opened here on Wednesday. (Xinhua/Lu Boan)

Actors from Vietnam give a performance during the 15th China-ASEAN (Association of Southeast Asian Nations) Expo held at the Nanning International Convention and Exhibition Center in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, Sept. 12, 2018. The expo opened here on Wednesday. (Xinhua/Lu Boan)

Dancers from Cambodia give a performance during the 15th China-ASEAN (Association of Southeast Asian Nations) Expo held at the Nanning International Convention and Exhibition Center in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, Sept. 12, 2018. The expo opened here on Wednesday. (Xinhua/Lu Boan)

People from Vietnam perform musical instruments during the 15th China-ASEAN (Association of Southeast Asian Nations) Expo held at the Nanning International Convention and Exhibition Center in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, Sept. 12, 2018. The expo opened here on Wednesday. (Xinhua/Zhou Hua)

Actresses from Myanmar give a performance during the 15th China-ASEAN (Association of Southeast Asian Nations) Expo held at the Nanning International Convention and Exhibition Center in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, Sept. 12, 2018. The expo opened here on Wednesday. (Xinhua/Lu Boan)