保温

heat preservation

♦ 积雪可以~保墒。 A layer of snow can preserve soil moisture and prevent it from freezing.

♦ 这个暖瓶不~。 This thermos flask doesn't keep the heat well.

~杯 thermos mug~材料 thermal insulation material~层 [建](thermal) insulating layer~车 [铁路]refrigerator wagon (or car)~瓶 vacuum flask (or bottle); thermos