IX. Read the text below and share your opinions about usefulness and side effects of natural medicine
A.Dandelion greens are edible and are a rich source of vitamin A. Dandelion has been used in many traditional medical systems, including Native American and traditional Arabic medicine. Historically, dandelion was most commonly used to treat liver diseases, kidney diseases, and spleen problems. Less commonly, dandelion was used to treat digestive problems and skin conditions. Today, traditional or folk uses of dandelion include use as a liver or kidney “tonic,” as a diuretic, and for minor digestive problems.
The leaves and roots of the dandelion, or the whole plant, are used fresh or dried in teas, capsules, or extracts. Dandelion leaves are used in salads or as a cooked green, and the flowers are used to make wine.
B.Dandelion use is generally considered safe. However, there have been rare reports of upset stomach and diarrhea, and some people are allergic to the plant.
People with an inflamed or infected gallbladder, or blocked bile ducts, should avoid using dandelion.
X. Answer the questions to the text:
What treatment: natural or conventional is more appropriate in the case of slight malaise? Give your reasoning.
Name methods of natural medicine that will definitely help to cure flu/grippe/cold.
Explain why you use/don’t use natural medicine achievements.
IV.
____________________________________________________________
Topic: Solutions
_____________________________________________________________
I. Practice the pronunciation of the following words and word combinations. Translate them:
1. solutionn. [səˈluːʃ(ə)n]
2. homogenous adj.[həˈmɒdʒɪnəs]
3. substance n.[ ˈsʌbst(ə)ns]
4. solvent n.[ˈsɒlv(ə)nt]
5. solute n. [sɒˈljuːt]
6. to dissolve v.[ dɪˈzɒlv]
7. heterogeneous adj.[ ˌhɛt(ə)rə(ʊ)ˈdʒiːnɪəs]
8. density n. [ˈdɛnsɪti]
9. lump n. [lʌmp]
10. to stir v. [stəː]
11. motion n. [məʊʃ(ə)n]
12. to encounter v.[ ɪnˈkaʊntə]
13. alloys n.[ ˈalɔɪ]
14. molecule n.[ ˈmɒlɪkjuːl]
15. soluble adj. [ˈsɒljʊb(ə)l]
II. Read and translate the text: Solutions
A solution is a homogenous mixture of substances with variable composition. The substance present in the major proportion is called the solvent, whereas the substance present in the minor proportion is called the solute. It is possible to have solutions composed of several solutes. The process of a solute dissolving in a solute is called dissolution.
Many common mixtures (like concrete) are heterogeneous —the components and properties of such mixtures are not distributed uniformly throughout their structures. Conversely, solutions are said to be homogeneous because they have uniform composition and properties. Solutions are intimate and random homogeneous mixtures of atomic-size chemical species, ions, or molecules.
In addition to their observed homogeneity, true solutions also have certain other characteristics. For example, components of a solution never separate spontaneously, even when a significant density difference exists between the components. Solutions also pass through the finest filters unchanged.
The components of a solution distribute themselves in a completely random manner, given sufficient time. For example, a lump of sugar dropped into a glass of water dissolves, and eventually molecules of sugar can be found randomly distributed throughout the water, even though no mechanical stirring has been employed. This phenomenon, called diffusion, is similar to the process of diffusion that occurs with gases. The molecules of sugar (as well as those of water) must be in constant motion in the solution. In the case of liquid solutions, the sugar molecules do not move very far before they encounter other molecules; diffusion in a liquid is therefore less rapid than diffusion in gas.
Kinds of solutions.Many commonly encountered solutions are those involving a solid that has been dissolved in a liquid, but there are as many types of solutions as there are different combinations of solids, liquids, and gases. Solutions in which the solvent is a liquid and the solute is a gas, liquid, or solid are very common. The atmosphere is a good example of a solution in which a gaseous solvent (nitrogen) dissolves other gases (such as oxygen, carbon dioxide, water vapor, and neon). Solutions of solids in solids are another example, and these are encountered most often among the various metal alloys.
Of all the liquid solvents used in the laboratory, in industry, and in the home, water is the most commonly employed and is the best of the inorganic solvents. The alcohols and numerous other types of compounds are classified as organic solvents; many of these are used in dry cleaning chemicals, nail polish removers, paint thinners, and many other similar purposes.
