The fuel gas which can be made by some bacteria that are some decomposers is: 1. oxygen
2. carbon monoxide
3.hydrogen
4. methane

Methane

Explanation:

When the oxygen available below ground is used up by fungi and bacteria, their decomposing activity stops. Easily decomposed organic substances will continue to be broken down by anaerobic bacteria, which can live where no oxygen exists. Methane gas is one of the products of their decomposing activity.

No, but they do work within their own system.

Explanation:

Although this collection of glands is considered a system, they do not work together in the way that the parts of the digestive system or the respiratory system work. Instead, they work independently, each with their own job to do and responding to the body's needs at any particular time.

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