frost-free period

例句：

1. 1. The region has a long frost-free period in winter.
   该地区冬季有很长的无霜期。
2. 2.Farmers can plant crops during the frost-free period.
   农民可以在无霜期种植作物。
3. 3.This region is known for its frost-free period and pleasant climate.
   这个地区以其无霜期和宜人的气候而闻名。