That 's the reality of being a mammal .

这是作为哺乳动物所要面对的一个事实。

Then a similar mammal was found in myanmar in 1990 .

后来在1990年一种与之类似的哺乳动物在缅甸被发现。

Researchers have produced a variant of h5n1 that reportedly can spread from one mammal to another .

研究人员已经制造出h5n1的一个变种，据说可以在哺乳动物之间传播。

But given a grain of cortex , it is not easy to tell from which mammal it came .

但是仅依靠一小块皮质，我们很难分辨出它到底取自哪种哺乳动物。

The problem with that theory is that no other mammal has resorted to this method of cooling down .

这一理论的问题在于，没有其他的哺乳动物采取了这种降低体温的方式。