Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)

Food is delivered to diners by way of gravity-powered rollercoaster tracks at a restaurant at the Raffles City shopping mall in Chongqing, Sept. 16, 2019. Robots also serve food to tables, and the unique delivery methods have attracted many customers. (Photo: China News Service)