Compare and Contrast watching a movie at home vs. at a movie theater.

At the theatre, the TV screen is huge. At home, it's much smaller. At the cinema, you sit in seats with cupholders. At home, you watch on the couch.

At the cinema, they dim the lights for you. At home, you have to take of the lights.

At the cinema, you have to pay for treats (popcorn, drinks, etc.)

At home,  you just take it out of the cupboard, but if you don't have, you buy from the store, which is much cheaper.  

halibut, flounder, tuna, and trout are all fish. so your first answer is 1.) fish. and since fish is edible, your next answer would be 3). edible

to describe those fishes more thoroughly, some of those fishes live in fresh water, and some of the fishes live in salt water, and that is not a thing that they all have in common. the question is asking what is common with all of the fish, so answer choices 2). fresh water and 4). salt water are not right.