Fill in the blanks.
(a) Microorganisms can be seen with the help of a ____________.
(b) Blue green algae fix __________ directly from air to enhance fertility of soil.
(c) Alcohol is produced with the help of __________.
(d) Cholera is caused by __________.
NCERT Class VIII
Science - Main Course Book
Chapter 2. Microorganisms: Friend and Foe