The figurative expression is at the heart if Lucy's paper. The paper does not actually have a heart, it means to say that the body of the paper or the main purpose of it. The comparison is between a heart and Lucy's paper.
This is in Romainian and it means Build a sentence in which numeral (fourfold, indest, sevenfold and thousandfold) have adjectival value (please, PS I kind of forgot :(
