Fill in the blanks.

(a) Microorganisms can be seen with the help of a …………… .

(b) Blue green algae fix …………… directly from air and enhance fertility of soil.

(c) Alcohol is produced with the help of …………… .

(d) Cholera is caused by …………… .

(a) Microorganisms can be seen with the help of a microscope .

(b) Blue green algae fix nitrogen directly from air and enhance fertility of soil.

(c) Alcohol is produced with the help of yeast .

(d) Cholera is caused by bacteria .