TASK DEFINITION: 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.
PROBLEM: zinc phosphate is a chemical compound.

SOLUTION: zinc phosphate

PROBLEM: land of the free is the national anthem of belize.

SOLUTION: land of the free

PROBLEM: the battle of the netherlands was part of the german invasion of france and the low countries (belgium, luxembourg, and the netherlands) during world war ii.

SOLUTION:
battle of the netherlands