Complete the sentence:
Conflicting standards for allowable radiation levels in foods made _________ appraisals of the damage to crops following the reactor meltdown extremely difficult.

“Reliable” means dependable. If one were to insert this term into the text, the sentence would read “Conflicting standards for allowable radiation levels in foods made reliable appraisals of the damage to crops following the reactor meltdown extremely difficult.” It makes sense that “conflicting,” or inconsistent, standards would affect the dependability of “appraisals” or estimates.