A sanitation worker collects wastes from an automatic cleaning machine in a river in Hangzhou, east China's Zhejiang Province, Oct. 21, 2020. A series of high-tech measures were applied to improve the river ecosystem in Hangzhou, including unmanned boats patrolling, automatic watercourse waste cleaning system, artificial intelligence (AI) monitoring system, etc. (Xinhua/Xu Yu)

An automatic cleaning machine collects wastes in a river in Hangzhou, east China's Zhejiang Province, Oct. 21, 2020. A series of high-tech measures were applied to improve the river ecosystem in Hangzhou, including unmanned boats patrolling, automatic watercourse waste cleaning system, artificial intelligence (AI) monitoring system, etc. (Xinhua/Xu Yu)

Aerial photo taken on Oct. 21, 2020 shows an unmanned patrolling and waste collecting machine works in a river in Hangzhou, east China's Zhejiang Province. A series of high-tech measures were applied to improve the river ecosystem in Hangzhou, including unmanned boats patrolling, automatic watercourse waste cleaning system, artificial intelligence (AI) monitoring system, etc. (Xinhua/Xu Yu)

A sanitation worker collects wastes from an unmanned patrolling and waste collecting machine by a river in Hangzhou, east China's Zhejiang Province, Oct. 21, 2020. A series of high-tech measures were applied to improve the river ecosystem in Hangzhou, including unmanned boats patrolling, automatic watercourse waste cleaning system, artificial intelligence (AI) monitoring system, etc. (Xinhua/Xu Yu)

Aerial photo taken on Oct. 21, 2020 shows an unmanned patrolling and waste collecting machine works in a river in Hangzhou, east China's Zhejiang Province. A series of high-tech measures were applied to improve the river ecosystem in Hangzhou, including unmanned boats patrolling, automatic watercourse waste cleaning system, artificial intelligence (AI) monitoring system, etc. (Xinhua/Xu Yu)

An unmanned patrolling and waste collecting machine works in a river in Hangzhou, east China's Zhejiang Province, Oct. 21, 2020. A series of high-tech measures were applied to improve the river ecosystem in Hangzhou, including unmanned boats patrolling, automatic watercourse waste cleaning system, artificial intelligence (AI) monitoring system, etc. (Xinhua/Xu Yu)