Permafrost
n. [地]永久冻结带
📖 牛津释义
permafrost
n[U]
subsoil that is permanently frozen, eg in polar regions 永冻土, 永冻层（如在极地的）.
🗣️ 情景例句
Keep a small English dictionary with you at all time.
随身携带一本小英文字典。
It's a worthwhile cause.
这是值得为之奋斗的事业。
Best wishes,
衷心地祝福你，