Question

To set up your fish aquarium, you must first decide where to put your tank. You should place your fish tank on a stable, sturdy piece of furniture, such as a table. Pick a spot away from direct sunlight, as direct sunlight can harm some fish. After placing your tank in its chosen spot, place a small layer of pebbles at the bottom of the aquarium. Then, put a few underwater plants or other decorations on top of the pebble layer. After adding decorations, fill the tank with water. Because the water will make the tank heavy, fill the tank by using a clean pitcher filled with water. That way, you will not have to move your tank after it is full of water. Finally, put your new fish into your aquarium.
Which of these details does NOT support or fit into this paragraph’s main idea?
A) Fill the tank with water until it reaches about three inches from the top.
B) Dogs are delightful pets indeed, but they also require a lot of responsibility.
C) The pebble layer should be about three inches thick and cover the entire bottom.
D) Make sure that any decorations you put in the tank are designed for fish aquariums.

Answer 1

B) Dogs are delightful pets indeed, but they also require a lot of responsibility

Answer 2

B, because nothing in this talks about dogs, and the main idea of the article is fish. It is more specifically about setting up a fish aquarium.