沙漠对大多数生命形式构成了恶劣的气候环境。

The desert presents a ___hostile climate for most forms of life.

科学家们在极其恶劣的条件下进行了研究。

The scientists conducted research in extremely ___hostile conditions.

许多移民最终生活在恶劣的居住环境中。

Many migrants end up in ___hostile living environments.