Lungs and legs.
sure
They have gills which enable them to breath underwater.
their gills
they are richly supplied with blood capilleries to absorb oxygen and they are also highly folded in order to increase the surface area for the simple process of diffusion to occur.
For short periods it is fine. For longer periods sickness will occur due to a lack of needed nutrients for tropical fish that is not found in goldfish food. This is from personal observances.
Fish have specialized parts (gills, fins, scales, for example) that enable the fish to live and breathe under water.
As long as you have done research about types of fish, the tank size needed, and you are prepared to put in the time it takes to care for fish which includes regular water changes, then you may be about to discuss it with your parents with more information.
A fish's lateral line feel changes in the water around it.
While it is not definitively proven, some research suggests that fish may exhibit behaviors that could be interpreted as mourning or sadness when another fish dies. This includes changes in behavior and interactions with the deceased fish. However, more research is needed to fully understand the emotional experiences of fish.
i don no
in their gills.
pufferfish