I only exist when you are here. Where you never were, I can never be. What am I?

Answer: Reflection

Solution:

An art­-form and a web-­browser.

Answer: opera

Solution:

Slayer of regrets, old and new, sought by many, found by few.

Answer: redemption

Solution:

I’m white, and used for cutting and grinding. When I’m damaged, humans usually remove me or fill me. For most animals I am a useful tool. What am I?

Answer: Tooth

Solution:

What has four fingers and a thumb but is not alive?

Answer: A glove

Solution:

Find the missing number in the box

Answer: 3.5+4.5=8 ; 9.5-3.5=6

Solution: