what is the omitted word in each lines

P>B Shelley is considered be one 

of greatest romantic poets of all times.

We all must experinced the pleasant

feeling of wind blowing us usually.

We find nothing unusal in it.

But for Shelley, it something unique

and special. The wind inspired to write great poems.

The required article is:

P.B.Shelley is considered to be one

of the greatest romantic poets of all times.

We all must have experienced the pleasant

feeling of wind blowing on us usually.

We always find nothing unusual in it.

But for Shelley, it is something unique

and special. The wind inspired him to write great poems.