A visitor looks at paintings displayed at an art exhibition in Lisbon, Portugal, March 13, 2019. About 30 paintings are on display at an art exhibition, which kicked off on Wednesday in Lisbon, to mark the 20th anniversary of the establishment of the Macao Special Administrative Region (SAR). (Xinhua/Zhang Liyun)

A visitor looks at paintings displayed at an art exhibition in Lisbon, Portugal, March 13, 2019. About 30 paintings are on display at an art exhibition, which kicked off on Wednesday in Lisbon, to mark the 20th anniversary of the establishment of the Macao Special Administrative Region (SAR). (Xinhua/Zhang Liyun)

A visitor looks at paintings displayed at an art exhibition in Lisbon, Portugal, March 13, 2019. About 30 paintings are on display at an art exhibition, which kicked off on Wednesday in Lisbon, to mark the 20th anniversary of the establishment of the Macao Special Administrative Region (SAR). (Xinhua/Zhang Liyun)

A visitor looks at paintings displayed at an art exhibition in Lisbon, Portugal, March 13, 2019. About 30 paintings are on display at an art exhibition, which kicked off on Wednesday in Lisbon, to mark the 20th anniversary of the establishment of the Macao Special Administrative Region (SAR). (Xinhua/Zhang Liyun)