The professor worked for 7 hours at a ________. 

Policeare________thedisappearanceoftwochildren.

Agoodworkerinakeyspotcould,so_______ashekeptupproduction,takeallthecoffeebreakshewanted.

Perseverance is a kind of quality and that is _______ it takes to do anything well.

OxfordAdvancedLearnersDictionary’,3rdEdition(1980),isamongthebest-knownBritish______dictionaries.