Answer the following question given this paragraph: Sebaceous glands are commonly called oil glands. They produce an oily substance called sebum. Sebum is secreted into hair follicles. Then it makes its way along the hair shaft to the surface of the skin. Sebum waterproofs the hair and skin and helps prevent them from drying out. Q: What oily substance prevents the hair and skin of living things from drying out? Choices: - pus - progesterone - pancreatic enzymes - sebum A:
sebum
Answer the following question given this paragraph: chlorine is added to an aqueous solution of bromide. iodine crystals are added to a solution of potassium bromide. Bromide is present in naturally occurring salt solutions called brines. Based on your answers, propose an effective method to remove bromide from brine. Q: Bromide is present in brines, which are naturally occurring solutions of what? Choices: - iron - calcium - magnesium - salt A:
salt
Q: Answer the following question given this paragraph: Figure 10.43 Diamond is extremely hard because of the strong bonding between carbon atoms in all directions. Graphite (in pencil lead) rubs off onto paper due to the weak attractions between the carbon layers. An image of a graphite surface shows the distance between the centers of adjacent carbon atoms. (credit left photo: modification of work by Steve Jurvetson; credit middle photo: modification of work by United States Geological Survey) You may be less familiar with a recently discovered form of carbon: graphene. Graphene was first isolated in 2004 by using tape to peel off thinner and thinner layers from graphite. It is essentially a single sheet (one atom thick) of graphite. Graphene, illustrated in Figure 10.44, is not only strong and lightweight, but it is also an excellent conductor of electricity and heat. These properties may prove very useful in a wide range of applications, such as vastly improved computer chips and circuits, better batteries and solar cells, and stronger and lighter structural materials. The 2010 Nobel Prize in Physics was awarded to Andre Geim and Konstantin Novoselov for their pioneering work with graphene. Q: Diamond is extremely hard because of the strong bonding between ______ in all directions? Choices: - consistent atoms - hydrogen atoms - liquid atoms - carbon atoms A:
A: carbon atoms
Question: Answer the following question given this paragraph: Models may be physical, conceptual, or mathematical. Q: Models may be physical, conceptual, or what else? Choices: - experimental - fundamental - theoretical - mathematical A:
Answer: mathematical
*Question*
Answer the following question given this paragraph: Sulfur enters the ocean in runoff from land, from atmospheric fallout, and from underwater geothermal vents. Some ecosystems rely on chemoautotrophs using sulfur as a biological energy source. This sulfur then supports marine ecosystems in the form of sulfates. Human activities have played a major role in altering the balance of the global sulfur cycle. The burning of large quantities of fossil fuels, especially from coal, releases larger amounts of hydrogen sulfide gas into the atmosphere. As rain falls through this gas, it creates the phenomenon known as acid rain, which damages the natural environment by lowering the pH of lakes, thus killing many of the resident plants and animals. Acid rain is corrosive rain caused by rainwater falling to the ground through sulfur dioxide gas, turning it into weak sulfuric acid, which causes damage to aquatic ecosystems. Acid rain also affects the man-made environment through the chemical degradation of buildings. For example, many marble monuments, such as the Lincoln Memorial in Washington, DC, have suffered significant damage from acid rain over the years. These examples show the wide-ranging effects of human activities on our environment and the challenges that remain for our future. Q: Acid rain is corrosive rain caused by rainwater falling to the ground through which gas? Choices: - sulfide dioxide - carbon dioxide - essential dioxide - sulfur dioxide A:
**Answer**
sulfur dioxide
(Q).
Answer the following question given this paragraph: The Sun is at the center of the solar system. Q: What is at the center of our solar system? Choices: - the moon - earth - the Kuiper Belt - the sun A:
(A).
the sun