Question

one (. ) the greatest mysteries of bird life(. ) migration or travelling. Today most of(. ) information (. ) migration has come( ) ringin young(. ) adult bird. the method of ringing bird has(. )very extensivelyand profitable employed(. )europe and america. FIllThe blanks b

Answer 1

1) of

2) is

3) the

4) about

5) by

6) and

7) been

8) in

Answer 2

One (of) the greatest mysteries of bird life (is) migration or travelling.

Today most of (the) information (about) migration has come (from) ringing young (and) adult bird.

The method of ringing bird has (been) very extensively and profitable employed (in) Europe and America.

The words which are filled in the blanks are indispensable elements of English grammar like prepositions and determiners.