Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Q: pipo de clown (english: pipo the clown) is a clown who became very popular on dutch television.

A: pipo de clown
****
Q: the long-beaked echidnas make up one of the two genera (genus zaglossus) of echidna.

A: long-beaked echidna
****
Q: the gakkel ridge (formerly known as the nansen cordillera and arctic mid-ocean ridge) is a mid-oceanic ridge.

A:
gakkel ridge
****