悉尼港惊现清洁机器人，开启环保新征程
Sydney Harbour has many boats. Boats use fuel (燃料). Fuel makes the air dirty. So a company made two robots.
The first robot is PBot. It cleans slime (黏液) from boats. Clean boats use less fuel. PBot helps keep water clean.
The second robot is CBot. It helps take spiky (有尖刺的) animals away, like sea urchins. These animals can hurt the ocean. CBot also takes photos for scientists.
The robots are useful. They help a lot.