Question 1 (b) Blue green algae fix ___ directly from air to enhance fertility of soil.
Fill in the blanks:
(a) Microorganisms can be seen with the help of a _________.
(b) Blue green algae fix _________ directly from air to enhancefertility of soil.
(c) Alcohol is produced with the help of _________.
(d) Cholera is caused by _________.