What goes up but never comes down?

What does this rebus mean?

O
N
C
E
TIME

What is the word or phrase below?
R | E | A | D

Can you find the key in the picture below?

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

Consider this: Arnold Schwarzenegger has a big one. Michael J. Fox has a small one. Prince doesn’t have one. The Pope has one but never uses it. Bill Clinton has one and uses it all the time. What is it?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?