Fill in the Blanks (Reading & Writing)

Citizen science projects invite members of the public to —collectcollectioncollectingcollected data on birds, weather or night skies, often through simple smartphone apps. Because volunteers vastly —outnumberoutnumberedoutnumberingoutnumbers the number of professional researchers, these projects can gather observations across a scale that no single institution could —achieveachievedachievingachievement alone.