instruction:
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.
question:
euclid's lemma, also called euclid's division lemma or euclid's first theorem, is an important lemma.
answer:
euclid's lemma


question:
the alkaline earth metals are the second group of metals on the periodic table.
answer:
alkaline earth metal


question:
veronika marchenko is a russian activist.
answer:

veronika marchenko