保护生态圈对维持地球上的生命至关重要。

Protecting the ___ecosphere is essential for sustaining life on Earth.

科学家们正在研究如何在火星上建立一个封闭的生态球系统。

Scientists are working on creating a sealed ___ecosphere for Mars colonization.

这个封闭的生态球里有小鱼和水草，不需要额外照料。

The sealed ___ecosphere contains small fish and aquatic plants, requiring no additional care.