A flag-raising ceremony is held during a grand gathering celebrating the Communist Party of China (CPC) centenary at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Pang Xinglei)

The national flag guards stand in formation during a flag-raising ceremony at a grand gathering celebrating the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Xin)

The national flag guards march during a flag-raising ceremony at a grand gathering celebrating the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Ma Ning)

The national flag guards march during a flag-raising ceremony at a grand gathering celebrating the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Xin)

The national flag guards march during a flag-raising ceremony at a grand gathering celebrating the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Shen Hong)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Lan Hongguang)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Yao Dawei)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Chen Zhonghao)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Ren Chao)

Military aircraft fly over Tian'anmen Square in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Zhang Chen)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Chen Jianli)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Ren Chao)

Military aircraft fly over Tian'anmen Square in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Yin Gang)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Dai Tianfang)

Military aircraft fly over Tian'anmen Square in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Rao Aimin)

Military aircraft fly over Tian'anmen Square in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Rao Aimin)

Representatives of the Chinese Communist Youth League members and Young Pioneers salute the Communist Party of China (CPC) and express commitment to the Party's cause at a ceremony marking the CPC centenary at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Zhai Jianlan)

Representatives of the Chinese Communist Youth League members and Young Pioneers salute the Communist Party of China (CPC) and express commitment to the Party's cause at a ceremony marking the CPC centenary at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Liu Bin)

Representatives of the Chinese Communist Youth League members and Young Pioneers salute the Communist Party of China (CPC) and express commitment to the Party's cause at a ceremony marking the CPC centenary at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Yin Bogu)

The stitched photo shows a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Ren Chao)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Ren Chao)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Li Mengjiao)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Dai Tianfang)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Chen Zhonghao)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Zhang Ling)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Zhang Ling)

Military aircraft fly over Tian'anmen Square in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Ren Chao)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Li Mengjiao)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Zhang Ling)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Zhang Haofu)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Chen Jianli)

The national flag guards march during a flag-raising ceremony at a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Lan Hongguang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Sun Fei)

Helicopters fly over Tian'anmen Square in the formation of "100" ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li He)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Chen Zhonghao)

Helicopters fly over Tian'anmen Square in the formation of "100" ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Liu Jinhai)

The national flag guards march during a flag-raising ceremony at a grand gathering celebrating the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Xing Guangli)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Shen Hong)

A national flag-raising ceremony is held at Tian'anmen Square during a ceremony marking the centenary of the Communist Party of China (CPC) in Beijing, capital of China, July 1, 2021. (Xinhua/Xing Guangli)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Jin Liwang)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Xin)

A national flag-raising ceremony is held at Tian'anmen Square during a ceremony marking the centenary of the Communist Party of China (CPC) in Beijing, capital of China, July 1, 2021. (Xinhua/Yin Gang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Luo Xiaoguang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Ju Huanzong)

A gun salute is fired during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Peng Ziyang)

The national flag guards march during a flag-raising ceremony at a grand gathering celebrating the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Xing Guangli)

A gun salute is fired during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Meng Tao)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Ga)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Chen Jianli)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Ju Zhenhua)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Liu Jinhai)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Liu Jinhai)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Luo Xiaoguang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Luo Xiaoguang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Ga)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Pang Xinglei)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Cai Yang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Luo Xiaoguang)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Yin Gang)

Doves are released to the sky at Tian'anmen Square in Beijing, capital of China, July 1, 2021. A ceremony marking the centenary of the Communist Party of China (CPC) was held at Tian'anmen Square in Beijing on Thursday morning. (Xinhua/Sun Fei)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Gang)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Yan Yan)

Military aircraft fly over Tian'anmen Square in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Jin Liwang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Xiang)

Balloons are released during a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Ju Zhenhua)

Helicopters fly over Tian'anmen Square in the formation of "100" ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Li Xiang)

Military aircraft fly over Tian'anmen Square in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Rao Aimin)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Li Gang)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Zhang Chenlin)

Military aircraft fly in echelon ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Xu Qin)

Military aircraft fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Han Mingkun)

Helicopters fly over Tian'anmen Square in the formation of "100" ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Xinhua/Xie Huanchi)

A national flag-raising ceremony is held at Tian'anmen Square during a ceremony marking the centenary of the Communist Party of China (CPC) in Beijing, capital of China, July 1, 2021. (Xinhua/Liu Jinhai)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Ga)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Xiang)

A ceremony marking the centenary of the Communist Party of China (CPC) is held at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Xinhua/Li Ga)