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

Input: Consider Input: Passage: Similarly, monoprotic bases are bases that will accept a single proton. Diprotic acids contain two ionizable hydrogen atoms per molecule; ionization of such acids occurs in two steps. The first ionization always takes place to a greater extent than the second ionization. For example, sulfuric acid, a strong acid, ionizes as follows: K a1 = more than 10 2 ; complete dissociation. Answer: accepts one proton

Output: What is the basic characteristic of monoprotic bases?

Input: Consider Input: Passage: The largest known virus, called mimivirus, is so large that scientists first mistook it for a bacterium. It was first discovered in amoeba, in 1992, and was identified as a virus in 2003. Scientists believe that mimivirus may cause certain types of pneumonia in humans. The core contains DNA, with the majority of the DNA in genes, and only 10% DNA of unknown function ("junk" DNA). Answer: mimivirus

Output: What is the largest known virus?

Input: Consider Input: Passage: Most metal objects are made of metal alloys rather than pure metals. Answer: metal alloys
Output: What are most metal objects made of?