O_er_t_o_

Complete the missing letters of the given word.

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

During which month do people sleep the least?