Which of the following is primarily produced by the activity of anaerobic bacteria on sewage?

Mohan was writing a report on the benefits of biogas:
$i$. It is cheap and safe
$ii$. Can be used for cooking
$iii$. Can be transported easily
$iv$. Causes pollution
Which one of the above statements has been reported incorrectly?

Select the correct sequence of anaerobic digestion during biogas production.

If bacteria grow on cellulosic material,they produce a large amount of which gas?

Identify the correct statements from the following:

In the given figure,what do '$R$' and '$P$' represent?