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

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

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