natural mutants的用法和樣例：
例句
- There is more than enough natural variability in nature to mask a direct connection, they say.
他們表示，自然界里有著太多的自然變異使其直接聯繫不易被察覺。 - But the usual causes of natural variability do not seem to explain the current trend, so scientists incline to the view that it is man-made.
但通常的自然變異原因似乎解釋不了目前的趨勢，所以，科學家傾向於認為這是人為的。
