What does an 'average adult' mean?

Which can be cut with a knife chromium or dysprosium? Is substance melts proof that a chemical change has occurred? What are the consequences of wildfires? Why do you need to know about karnaugh maps? Which property of the Solar Nebula was the most influential in giving the planets their characteristics? Is body armor on required sources? What is portion of our planet in which ecosystems operate is known as the what? How do chloroplast get energy from sunlight? What is the role of chemistry in medicine industry? Is lead more reactive than magnesium? When is an apostrapy used? What intrinsic property of Venus makes it very reflective of light? Why is homogeneous not considered as pure substance? What prevents the emission of blowby gases? What human body system is injured when an ankle is sprained? When scientists use a what for an organism they can be certain they are all discussing the same organism? Nutrients move through ecosystem in different way.which nutrient cycles through organisms rivers rain and the atmosphere? What properties of air will produce a thunderstrom? How do scientist classify a camel as a animal? Which secretion does not contain different enzymes?

What does an 'average adult' mean?