In this task, you need to write a topic word from the given fact. The topic word must have at least one word overlap with the given fact. The topic word often involves adding a new word from a related concept. In your topic word, use at least one word from the given fact. Topic words with two or more words work best.

Fact: Plasma cells are activated B cells that secrete antibodies.
antibodies fight infection.

Fact: Placental mammals are therian mammals in which a placenta develops during pregnancy.
human placental.

Fact: Most salamanders use their sense of smell to find a mate.

Salamander.