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. (Photo: Xinhua)

Helicopters fly in echelons ahead of a grand gathering celebrating the Communist Party of China (CPC) centenary in Beijing, capital of China, July 1, 2021. (Photo: Xinhua)

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. (Photo: Xinhua)

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. (Photo: Xinhua)

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. (Photo: Xinhua)

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. (Photo: Xinhua)

Chorus members perform 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. (Photo: Xinhua)

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. (Photo: Xinhua)

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. (Photo: Xinhua)

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. (Photo: Xinhua)

Members of the military band rehearse for a ceremony marking the centenary of the Communist Party of China (CPC) at Tian'anmen Square in Beijing, capital of China, July 1, 2021. (Photo: Xinhua)

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. (Photo: Xinhua)

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. (Photo: Xinhua)

Chorus members perform 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. (Photo: Xinhua)

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. (Photo: Xinhua)