My friend ... a rhino. a)has never seen b)didn't see.

My friend has never seen a rhino. 

Мой друг никогда не видел носорога.

Has my friend never seen a rhino?

Has my friend never seen a rhino or a hippo?

What animal has my friend never seen?

What has my friend never seen?

Whose friend has never seen a rhino?

Who has never seen a rhino?

My friend has never seen a rhino, has he?