In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Example input: The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Example output: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.
Example explanation: The output sentence elaborates on the input sentence without changing its general meaning e.g. "tetralogy of young adult high fantasy novels".
Q: They needed a tool to cut DNA at specific sites , rather than at random sites along the length of the molecule .
A:
What was then needed was a tool that would cut DNA at specific sites , rather than at random sites along the length of the molecule , so that scientists could cut DNA molecules in a predictable and reproducible way .