Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

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?

No matter how little or how much you use me, you change me every month. What am I?

What jumps when it walks and sits when it stands?

What word is pronounced the same if you take away four of its five letters?

What is the word or phrase?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?