The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence. 

Safar’s work began to change our perceptions of death - blurring the point that is meant to mark the end of our lives. “We’ve all been brought up to think death is an absolute moment - when you die you can’t come back. It used to be correct, but now we’ve come to understand that even after you’ve become a cadaver, you’re still retrievable.” 

The boundary between life and death is less and less （）