

MCQOPTIONS
Saved Bookmarks
1. |
What is biogas composed of? |
A. | O<sub>2</sub> and CO<sub>2</sub> |
B. | CO<sub>2</sub> and NO<sub>2</sub> |
C. | CH<sub>4</sub> and O<sub>2</sub> |
D. | CH<sub>4</sub> and CO<sub>2</sub> |
Answer» E. | |