Simple riddles

What was the biggest island in the world before the discovery of Greenland by viking Erik the Red?

I am a home of knowledge, both banal and profound. In grand halls and small homes I can be found. I am a home for things of many leaves, but my many residents are not living trees. What am I?

At night they come without being fetched. By day they are lost without being stolen. What are they?

What comes down and goes up again and again? What is that?

I eat other animals. I have a big mouth. I am green. I live in the water. Who am I?

What has a neck but no head?

When you have me, you feel like sharing me. But, if you do share me, you don't have me. What am i?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth I am dissolved into air. What am I?

It can fill a room without occupying space. What is that?

When I look at her, she smiles at me. When I wink at her, she winks at me. When I kiss her, she kisses me back. When I say I love you, she says it back. Who am I?