the sixty-four-dollar question 基本问题，关键问题，最重要的问题，最后和最难的问题

【例句】
The sixty-four-dollar question now is whether he should choose his former opponent as a running mate.
现在关键问题是他是否应该选择他以前的对手作为竞选伙伴。

The sixty-four-dollar question of the company is out of funds.
这家公司的关键问题是缺乏资金。