" The discovery that, friction excluded, all bodies fall at the same rate is so simple to state and to grasp that there is a tendency to ____ its significance ".
I actually circled down to " praise " because the discovery is so simple to state and grasp that it’s praised. I didn’t think " underrate " would be correct because then it’d be like creating a story? That a discovery is so simple to state and grasp that it’s underrated. I mean, I felt there is no evidence to say that it’s underrated except the outside info. / theory that when things are simple, it’s not valued and is underrated. While the direct meaning only says such discovery is praised.