Swamps or maybe those in the desert. In swamps, the soil is too loose for animals to burrow without it caving in. In deserts, since the climate "rising" its getting to hot and dry for animals to burrow without the sand caving in when an animal walks above it.
<span>Stem cells. There are two types of stem cells: adult stem cells - these are unspecialised cells that can develop into many (but not all) types of cells. Embryonic stem cells - these are unspecialised cells that can develop into any type of cell. And that's all! ;)
Hope this is useful !!!^_~!!!</span>
You don’t have any options so idk
