Answer these riddles.?!

Answer these riddles.?

1) Until I am measure I am not known.Yet how you miss me, When I have flown.
What am I?

2) What object has keys that open no locks, space but no room, and you can enter but not go in.
What am I?

3) There is a clerk at the butcher shop, he is Five Feet ten inches, and he wears size 13 sneakers. He has a wife and 2 kids. What does he weigh?

2 weeks ago
sorry first one has a typo should be measured not measure.

1. time
2.keyboard
3.meat