Sentence examples for has sometimes been challenging from inspiring English sources

Whereas this approach has sometimes been challenging [ 36], in large part it has proven successful in bacteria and the yeast Saccharomyces cerevisiae.

Blaug's and Hutchison's criticisms have sometimes been challenged on the grounds that economic theories cannot be tested, because of their ceteris paribus clauses and the many subsidiary assumptions required to derive testable implications (Caldwell 1984).

She says that it has sometimes been a challenge to be married to a man of Ramachandran's mental energy and intellectual curiosity.

Nor will it be the athletically challenging experience it has sometimes been in the past.

Evidence has sometimes been mishandled.

It has sometimes been difficult.

An element of tension arises because the logic of puja and prasada seems to accord all humans an equal status with respect to God, yet exclusionary rules have sometimes been sanctified rather than challenged by prasada-based ritual.

For all their bizarre equivocation over the Human Rights Act, in recent years the Tories have sometimes been on the right side in specific challenges to individual liberty.

Honours have sometimes been forfeited.

I've sometimes been mad, sometimes sad.

Denominators have sometimes been unclear.