energy後面跟什麼

後面跟介詞或者什麼都不加，例如：

1、The system produced enough energy to heat several thousand homes.系統產生的能量足以給幾千戶人家供暖。

2、In the exam there's sure to be a question on energy.考試時準有關於能量的題目。

3、It's a waste of time and energy.那是浪費時間和精力。