Question

The to roll the invalidity to roll the tongue is caused by

Answer 1

Answer:

It's long been thought that the ability to roll your tongue is a clear-cut case of genetics. ... The reason we couldn't all do it, we were told, is because it is a simple genetic trait. You had either inherited the right variant of the tongue-rolling gene or you hadn't. And if you hadn't, you would never be able to do it. 30-Jan-2018

Explanation:

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