Answer the following question given this paragraph: Figure 12.11 shows schematically how laminar and turbulent flow differ. Layers flow without mixing when flow is laminar. When there is turbulence, the layers mix, and there are significant velocities in directions other than the overall direction of flow. The lines that are shown in many illustrations are the paths followed by small volumes of fluids. These are called streamlines. Streamlines are smooth and continuous when flow is laminar, but break up and mix when flow is turbulent. Turbulence has two main causes. First, any obstruction or sharp corner, such as in a faucet, creates turbulence by imparting velocities perpendicular to the flow. Second, high speeds cause turbulence. The drag both between adjacent layers of fluid and between the fluid and its surroundings forms swirls and eddies, if the speed is great enough. We shall concentrate on laminar flow for the remainder of this section, leaving certain aspects of turbulence for later sections. Q: Streamlines are smooth and continuous when flow is laminar, but break up and mix when flow is what? Choices: - atmospheric - volcanic - slow - turbulent A:
turbulent
Answer the following question given this paragraph: Echinoderms are found in many different ocean environments, but most are found in reefs. Q: Echinoderms are found in many different ocean environments, but most are found where? Choices: - in tidepools - in beaches - in waterfalls - in reefs A:
in reefs
Q: Answer the following question given this paragraph: The higher up a food chain that humans eat, the greater the levels of toxic metals they take in. That's why people should avoid eating too much of large fish such as tuna. Tuna are predators near the top of their food chains. They have been shown to contain high levels of mercury. In people, heavy metals can damage the brain and other organs. Unborn babies and young children are most affected. That's because their organs are still developing. Q: Tuna have been shown to contain high levels of what metal? Choices: - cadmium - titanium - iron - mercury A:
A: mercury
Question: Answer the following question given this paragraph: The Salivary Glands Many small salivary glands are housed within the mucous membranes of the mouth and tongue. These minor exocrine glands are constantly secreting saliva, either directly into the oral cavity or indirectly through ducts, even while you sleep. In fact, an average of 1 to 1.5 liters of saliva is secreted each day. Usually just enough saliva is present to moisten the mouth and teeth. Secretion increases when you eat, because saliva is essential to moisten food and initiate the chemical breakdown of carbohydrates. Small amounts of saliva are also secreted by the labial glands in the lips. In addition, the buccal glands in the cheeks, palatal glands in the palate, and lingual glands in the tongue help ensure that all areas of the mouth are supplied with adequate saliva. Q: What small glands are abundant within the mucous membranes of the mouth and tongue? Choices: - hypothalamus glands - retinal glands - localized glands - salivary glands A:
Answer: salivary glands
*Question*
Answer the following question given this paragraph: where the (am) designation refers to an ammonia solution, analogous to (aq) used to indicate aqueous solutions. Without a catalyst, the reaction in Equation 21.20 tends to be rather slow. In many cases, the alkali metal amide salt (MNH2) is not very soluble in liquid ammonia and precipitates, but when dissolved, very concentrated solutions of the alkali metal are produced. One mole of Cs metal, for example, will dissolve in as little as 53 mL (40 g) of liquid ammonia. The pure metal is easily recovered when the ammonia evaporates. Solutions of alkali metals in liquid ammonia are intensely colored and good conductors of electricity due to the presence of solvated electrons (e, NH3), which are not attached to single atoms. A solvated electron is loosely associated with a cavity in the ammonia solvent that is stabilized by hydrogen bonds. Alkali metalliquid ammonia solutions of about 3 M or less are deep blue (Figure 21.11 "Alkali MetalLiquid Ammonia Solutions") and conduct electricity about 10 times better than an aqueous NaCl solution because of the high mobility of the solvated electrons. As the concentration of the metal increases above 3 M, the color changes to metallic bronze or gold, and the conductivity increases to a value comparable with that of the pure liquid metals. Q: In many cases, the alkali metal amide salt (mnh2) is not very soluble in liquid ammonia and does what? Choices: - settles - isolates - evaporates - precipitates A:
**Answer**
precipitates
Answer the following question given this paragraph: Q: Abundant in unpolluted ponds and streams, planarians prey on smaller animals or feed on? Choices: - algae - fungi - unidentified animals - dead animals A:
dead animals