Input (grade 13): DelbrÃ 1\/4 ck's efforts to promote the "Phage Group" (exploring genetics by way of the viruses that infect bacteria) was important in the early development of molecular biology.
Output (grade 11): DelbrÃ 1\/4 ck's big idea was to explore genetics by means of the bacteriophage viruses which infect bacteria. This was important in the early development of molecular biology.