Photo taken on March 13, 2021 shows the sunset scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Aerial photo taken on March 13, 2021 shows the sunset scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Aerial photo taken on March 13, 2021 shows the scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Aerial photo taken on March 13, 2021 shows the scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Photo taken on March 13, 2021 shows the scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Aerial photo taken on March 13, 2021 shows the sunset scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Aerial photo taken on March 13, 2021 shows the scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)

Photo taken on March 13, 2021 shows the scenery of Xingkai Lake, a border lake between China and Russia. (Xinhua/Xie Jianfei)