任务书的英文：
requirement
The prime contractor and the software subcontractor agree to their commitments to each other.
主签约人和子签约人互相接受他们的任务书。
n. 需要；必需品；要求；必要条件；规定
Is the requirement compulsory?
必须按这个需求做吗？
In practice, this will often require a prioritization of your job requirements.
实务上，这往往需要重新调整工作的优先顺序。
All systems requiring accurate timing will require a crystal.
所有需要精确定时的系统都要用晶体。
Excision of an obnoxious passage was required.
有一段引起反感的文字必须删掉。
require or ask for as a price or condition.
要求或者请求价格或者社会地位。