Because of the cold temperatures, the tundra has two layers: top layer, which is called the active layer, is frozen in the winter and spring, but thaws in the summer.

由于寒冷的气温，冻土带有两层：最上面的一层被称为活动层，在冬季和春季被冻结，但在夏季解冻。

youdao

We don't have winter here, everyday is spring, snow and frozen could only be seen in the mountain and fridge.

我们这里没有冬天，每天都是春天；下雪和冰冻只能在山上和冰箱里才看得到。

youdao

If the ground hasn't frozen yet, plant spring-flowering bulbs such as crocus , daffodils, tulips and hyacinths as soon as possible to beat the odds.

如果泥土还未冻结，抓紧时机种下番红花，水仙，郁金香和风信花的球茎。

youdao

Everything they said remained frozen all winter long, and did not melt until spring.

VOA: special.2009.01.24

Despite it being the middle of April, that spring was exceptionally cold and the waterfalls that streak the mountains were frozen over.

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The seasonal increase results from tons of carbon dioxide, which had been frozen into a southern winter ice cap, returning into the atmosphere as southern spring turns to summer.

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