From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.
--------
Question: Given Relationship: 'be key to', Sentence: 'As present processes are thought to explain all past events , the Uniformitarianism slogan is " the present is the key to the past . "'

Answer: key


Question: Given Relationship: 'be form of', Sentence: 'This suggests that ATIVAN is a very buried form of ASD.'

Answer: form


Question: Given Relationship: 'be country in', Sentence: 'Bulgaria is beautiful small country situated in south-eastern Europe .'

Answer:
country