Appositives: Box the appositive/appositive phrase in each sentence. Oceanography, the study of the ocean, often requires courage.

The submersible Alvin can dive very deep.

My best friend, Sammy, lives in Cleveland.

My brother's car, a sporty red convertible with bucket seats, is the envy of my friends.

The chief surgeon, an expert in organ-transplant procedures, took her nephew on a hospital tour.