Oversea Chinese visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese wait to visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese view a scene of China's national college entrance examination in 1977 at a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)

Oversea Chinese visit a grand exhibition of achievements in commemoration of the 70th anniversary of the founding of the People's Republic of China (PRC) at the Beijing Exhibition Center in Beijing, capital of China, Sept. 28, 2019. Some 2,000 oversea Chinese were invited to visit the exhibition on Saturday. (Photo: Xinhua)