If any young elephants are in the herd, the mothers frequently prove awkward customers.
Shafts were often blocked, levels frequently proved dead ends.
Like anyone who doubts his own power, Torvald must frequently prove it.
Although males can produce silk, they mostly use it in the mating ritual, which frequently also proves fatal.
Alcibiades' military and political talents frequently proved valuable to whichever state he worked for.
They frequently proved unreliable in service and several were substantially rebuilt, with new engines.
And whatever this or that survey may say, once broken, the bond of trust between two people frequently proves impossible to repair.
For a long time he served as the head of Argentina's delegation to the institution but he frequently proved a controversial choice.
Thus, the intra- and interjurisdictional comparison required by the Solem test would frequently prove unworkable.
A greater understanding of analysis in more abstract spaces frequently proves to be directly applicable to classical problems.