There were resources such as coal, iron, gold, and copper deep in the soil, but they remained________. A: discovered B: to discover C: being undiscovered D: undiscovered

Genetically engineered crops are sometimes released into the environment before they have been _________. A: slip by undiscovered B: health effects C: adequately tested D: public relations exercise

In terms of the data relationships found by data mining, associations refers to: A: patterns that describe a group to which an item belongs. B: occurrences linked to a single event. C: undiscovered groupings. D: events linked over time.