My grammar book says that you can say "the dog," "a dog" and "dogs" to refer dogs. This book says "dogs" is the most casual and common way of saying that among the three.
So, I wanted to say like this:
Some pets are more popular than others. I think one of them is dogs.
One and is don't seem to fit "dogs." How can I say that properly? "Some of them are dogs"?
*I don't know which tag I should put