Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: Large viruses were once parasitic cells inside bigger host cells. Over time, genes needed to survive and reproduce outside host cells were lost. Answer: parasitic

Answer: Large viruses began as what type of cells inside bigger host cells?

Question: Passage: Condensation reactions are the chemical processes by which large organic compounds are synthesized from their monomeric units. Hydrolysis reactions are the reverse process. During condensation reactions, water is produced from the two molecules being bonded together; an H from one monomer is joined to an -OH from another molecule, producing H 2 O. Answer: water

Answer: What is produced during a condensation reaction?

Question: Passage: Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors . Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. That's why the metal pot in Figure above soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure below , the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. Answer: thermal conductors

Answer:
What are materials that are good conductors of thermal energy called?