Fill in the blanks:
The conversion of fertile land into deserts is called……….

The fertile land between two rivers is called

The fertile land between two rivers is called

Fertile leaves of ferns are called

The conversion of ammonia to nitrates is called .........

Fill in the blanks: The combination of two or more cells is called a ________.

Fill in the blanks : Succession that starts on a bare rock is called …………….. and that which begins on sand is called ……….. .

Conversion of spermatois to a spermatozoan is called :

Fill in the blanks: The average weather taken over a long time is called __________.