But all of these mummies were either scavenged by animals or partly destroyed by the freezing and thawing.

但所有这些木乃伊要么被动物捡拾，要么被冻融部分摧毁。

They are composed of heavy, compacted snow, which has been subjected to frequent alternations of freezing and thawing.

它们由厚重、压实的雪组成， 经过频繁的冻融交替。

After 20 to 30 years, natural processes like concrete shrinkage, excessive freezing and thawing, and heavy loads can trigger cracking.

20 到 30 年后，混凝土收缩、过度冻融和重载等自然过程会引发开裂。