![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
P: U4_3_3_1.mp3: Q3: How did inventors improve the original toilet according to the passage?
A.
They improved the pipes that were attached to the bottom.
B.
They added a knob on the chain to pull more easily.
C.
They improved the flush system to make it less water-consuming.
D.
They improved the collection bowl to make it more sanitary.