Good Riddles

Question: Which word does not belong in the following list:

Stop cop mop chop prop shop or crop?

Question: I have a name that's not mine,
and no one cares about me in their prime.
People cry at my sight,
and lie by me all day and night.

What am I?

Question: An iron horse with a tail of flax. The more the horse gallops, the longer his tail becomes.

Question: Two people are born at the same moment, but they don't have the same birthdays.

How could this be?

Question: I'm written with two letters, said with one and seen with two.What am I?