Christmas Secrets

I know so many secrets

Such secrets full of fun;

But if you hear my secrets,

Please don't tell anyone. 

Here are some lights that twinkle,

Here is an ornament.

Here is a great big present 

From grandpa, it was sent.

And on the very tip-tip top,

An angle you can see,

What is the secret? Can't you tell? 

Why it's a Christmas tree.