To "cool one's heels" -to be forced to wait a long time at some place, like a busy doctor's office or at an employment agency looking for a job.

“晾脚后跟”指一个人被迫在某地等候很久，如在忙碌的医生的候诊室久等，或在职业介绍所等待工作。

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Without Congressional action, the current wait for an employment-based green card can be 5 to 20 years or more, depending on the country of origin.

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He said he would recommend that anyone leaving government employment should wait for at least two years before being able to join a lobbying firm.

BBC: News | UK Politics | Toughen lobby codes - Draper

Moreover, reform is needed for green cards (permanent residence), since newly sponsored skilled foreign nationals, particularly from India and China, could wait years or decades for an employment-based green card.

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