Photo taken on Oct. 14, 2019 shows the autumn scenery in Berlin, Germany, on Oct. 14, 2019. (Photos: Xinhua)

Photo taken on Oct. 18, 2019 shows the autumn scenery of the Palmengarten in Frankfurt, Germany, on Oct. 18, 2019.

Photo taken on Oct. 14, 2019 shows the autumn scenery of the Tiergarten in Berlin, Germany, on Oct. 14, 2019.

Photo taken on Oct. 18, 2019 shows the autumn scenery of the Palmengarten in Frankfurt, Germany, on Oct. 18, 2019.

Photo taken on Oct. 18, 2019 shows the autumn scenery of the Palmengarten in Frankfurt, Germany, on Oct. 18, 2019.