Senator Roland Burris also blasted the program, and the U.S.government's contract with Boeing for the work, during this exchange with Customs and Border Protection Agency commissioner Alan Bersin.

VOA: standard.2010.04.21

to bring people on in short-term contract work.

关于雇佣短期合同工。

英国的影视产业 - SpeakingMax英语口语达人

You can prove that, in fact, if you were writing a contract, if there was a social planner you'd work more.

事实上你会发现,如果有书面合同,或者有个规划师的话人们会超常发挥

耶鲁公开课 - 博弈论课程节选

Why wouldn't writing a contract here work?

为什么他们不能签这样的合同

耶鲁公开课 - 博弈论课程节选