the other, others, the others, another

There are two options for lunch today. One is pasta, and (a)   is salad.

I have two cats; one is black, and (a)   is white.

We have two dogs. One is a poodle, and (a)   is a Labrador.

I bought two dresses. One is red, and (a)   is blue.

She has two cars. One is red, and (a)   is blue.

We visited Paris last year, and this year we plan to explore (a)   cities in Europe.

I don’t like this shirt. Is there (a)   one in the store?

I enjoyed one movie last night; let’s watch (a)   tonight.

We tried one restaurant yesterday; let’s explore (a)   for lunch today.

Some students finished their assignments early, while (a)   struggled to complete theirs.