By yesterday, Ukraine had already made agreements with 12 countries to obtain nearly 1,000 units of power equipment, including generators.

截止到昨天，乌克兰已与12个国家达成协议，获得了近1000台电力设备，包括发电机。

Suppliers bid according to how much it would cost to provide an extra unit of power, known as its marginal cost.

供应商根据提供额外单位电力的成本（即边际成本）进行投标。