Sisyphean task

    徒劳无功的苦差事

    A: Many scientists see the battle against infectious disease as a Sisyphean task.

    B: Why? Haven't we achieved great progress in controling many types of them?

    A: But no sooner do we gain control over one disease than another pops up.

    Note: A Sisyphean task is a tedious, repetitive job where people make no progress. Sisyphus is a king of Corinth in Greek mythology, punished in Hades for his misdeeds by eternally having to roll a heavy stone up a hill. Every time he approached the top, the stone escaped his grasp and rolled to the bottom. Hence, people liken repetitive and endless jobs of that type and nature to the unenviable job of Sisyphus.