A: I've never had this kind of crab before. What's it called? 我从来没吃过这种螃蟹。它叫什么？

B: It's a mitten crab. It's called that because of the fur on its claws. 中华绒螯蟹（大闸蟹）。它叫大闸蟹是因为它钳子上有毛。

What's it called? 它叫什么？

claws 钳子

Mitten crab 大闸蟹

It's called... 这叫…

What's something called? …叫什么？

A: What's that thing that opens the wine bottle called? 那个把酒瓶打开的东西叫什么？

B: It's called a corkscrew. 那叫开瓶器。

corkscrew 开瓶器