How can you make number one disappear by adding something to it?

O_er_t_o_

Complete the missing letters of the given word.

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

There's a day, that comes around once a year.
To celebrate the man, you hold dear.
He gave you life, love and will pick you up if you fall.
When it comes to guys like him, He's the best of all.
Who is he?

What does below Rebus say?

XLR8

The Little ant seems to be always confused. Do you know why?

In the image given, you can find several triangles. Can you count them all?