Task: Text Simplification
Input (English): the exact nature of the transforming principle -lrb- dna -rrb- was verified in the experiments done by avery , mcleod and mccarty and by hershey and chase.
Output (English): 1 . the true nature of the changing principle -lrb- dna -rrb- was verified in the experiments done by avery , mcleod , mccarty , hershey , and chase.