Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

hiragana are part of the japanese writing system.
hiragana

dorothea sally eilers (or just sally eilers; december 11, 1908 – january 5, 1978) was an american actress.
sally eilers

the nissan maxima is an automobile produced by nissan motor company in seven generations since 1981.

nissan maxima