The main characteristics of fish are that they live in water all their lives, breathe with gills and swim with fins, and most of them have scales. (2) bearded fish (4) eel (6) tuna? (8) pomfret? (10) Jealous fish. They all breathe with their gills and swim with their fins. They belong to fish because they have the characteristics of fish.

(1) Squid is a mollusk with a soft body and mantle. ? (3) Carpet is a wingless insect, which belongs to Carpathidae and is also the general name of Carpathidae. It is a primitive small wingless insect with more than 100 species in the world, commonly known as whitefish, wallfishes and bookworms. ? (5) giant salamander? Belongs to amphibians; (7) Crocodiles belong to reptiles; (9) Whales live in water, but they breathe with their lungs, viviparous and have a constant body temperature, so they are mammals.

So choose D.