very promising
very promising approach
very promising candidates
very rapid
very rare
very rare case

very rare complication
very rare condition
very rare entity
very rare event
very relevant
very reliable
very resistant

very rich
very robust
very safe
very satisfactory
very satisfactory results
very scarce
very selective

very sensitive
very sensitive method
very severe
very shallow
very sharp
very short
very short duration

very short period
very short reaction times