那个陈旧、低效的供暖系统浪费了大量的能源和金钱。

The old, ___inefficient heating system wastes a lot of energy and money.

一台低效的空调在炎热的天气里无法使房间充分降温。

An ___inefficient air-conditioner fails to cool the room properly on hot days.

他低效的工作方法常常导致项目延期。

His ___inefficient working methods cause frequent delays in the project.