One is the bid, which is what they'll pay you for a Treasury bill if you want to sell to them.

一个是买入价,就是买方愿意支付给卖方的报价,如果你想卖给他们的话

耶鲁公开课 - 金融市场课程节选

The ask is what you have to pay them through this formula.

而卖出价就是,依据公式得出卖方的开价

耶鲁公开课 - 金融市场课程节选