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

Q: Passage: Figure 12.7 Statues made from carbonate compounds such as limestone and marble typically weather slowly over time due to the actions of water, and thermal expansion and contraction. However, pollutants like sulfur dioxide can accelerate weathering. As the concentration of air pollutants increases, deterioration of limestone occurs more rapidly. (credit: James P Fisher III). Answer: air pollutants

A: Deterioration of limestone occurs more rapidly as the concentration of what increases?
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Q: Passage: Translation is the process of ordering the amino acids in the assembly of a protein. The word ribosome comes from ribo nucleic acid and the Greek soma (meaning body). Two Nobel Prizes have been awarded for work relating to the ribosome. The 1974 Nobel Prize in Physiology or Medicine was awarded to Albert Claude, Christian de Duve and George Emil Palade for the discovery of the ribosome, and the 2009 Nobel Prize in Chemistry was awarded to Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for discovering the detailed structure and mechanism of the ribosome. Answer: protein

A: Translation is the process of ordering the amino acids in the assembly of a?
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Q: Passage: Attached to the placenta is the amniotic sac , an enclosed membrane that surrounds and protects the fetus. It contains amniotic fluid , which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. Answer: amniotic sac

A:
What is the enclosed, fluid-filled membrane that surrounds and protects the fetus and is attached to the placenta?
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