沙漠以其严酷的条件而闻名，白天酷热，夜晚严寒。

The desert is known for its ___harsh conditions, with scorching days and freezing nights.

极地探险家必须忍受北极的恶劣环境来进行研究。

Polar explorers must endure the ___harsh environment of the Arctic to conduct their research.

很少有植物能在高海拔地区的恶劣气候中生存。

Few plants can survive the ___harsh climate found at high altitudes.