Definition: a difficult or important piece of work, especially one that takes a long time Level: C2
建造自己的房子是一项重大的任务。
Building your own house is a major ___undertaking.
虽然这样的任务非常可取，但我想指出可能存在缺点。
While such an ___undertaking is most advisable, I should like to point out that there may be drawbacks.
组织这次国际会议被证明是一项复杂的任务。
Organising the international conference proved to be a complex ___undertaking.
