Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: Sperm ( Figure below ), the male reproductive cells, are tiny. In fact, they are the smallest cells in the human body. What do you think a sperm cell looks like? Some people think that it looks like a tadpole. Do you agree?. Answer: sperm

Output: What are the male reproductive cells called?

Input: Consider Input: Passage: Bacteria change nitrogen gas from the atmosphere to nitrogen compounds that plants can absorb. Answer: bacteria

Output: What changes nitrogen gas from the atmosphere to nitrogen compounds that plants can absorb?

Input: Consider Input: Passage: A nonmetal is an element that is generally a poor conductor of heat and electricity. Many properties of nonmetals are the opposite of those seen in metals. There is a wider variation in properties among the nonmetals than among the metals, as seen in Figure below . Nonmetals exist in all three states of matter at room temperature. The majority are gases, such as nitrogen and oxygen. Bromine is a liquid, and a few are solids, such as carbon and sulfur. In the solid state, nonmetals are brittle, meaning that they will shatter if struck with a hammer. The solids are not lustrous, and their melting points are generally much lower than those of metals. On the periodic table in the Figure above , the nonmetals are shaded green and appear to the right of the stair-step line. Answer: nonmetal
Output: An element that is generally a poor conductor of heat and electricity is known as a ______