by後面加什麼詞性?

All the statistical computations were performed by the new software system.

所有的統計計算均由新的軟件系統完成。

They won by a single goal after extra time.

他們在加時賽中僅踢進一球即獲勝。

They've increased the price by 50%.

他們已經把價格提高了50%。

Now I can walk to work instead of going by car.

現在我可以步行去上班，而不必開車了。

I'm always broke by the end of the month.

我總是一到月底就沒錢花了。