Question 1: Choose the item among A, B, C or D thai best answers the question about the passage:
"Desert is the term applied to regions of the earth that are used by less than 254 mm (10. inches) of annual rainfall an evaporation rate that exceeds precipitation, and, in most cases, a high average temperature. Because of a lack of moisture in the soil and low humidity in the atmosphere, most of the sunlight penetrates to the ground. Daytime temperatures can reach 55° c (131° F) in the shade. At night the desert floor radiates heat back to the atmosphere, and the temperature can drop to near freezing. Deserts are caused by a combination of climate patterns and geological features. Because so little water moves through the desert soil to carry nutrients away, desert soils are naturally fertile. Crops are grown on desert lands with water provided by irrigation from rivers or wells. Such transformations of deserts are not without problems. Evaporation of the irrigation water results in the accumulation of salt on the surface soil, eventually rendering it useless for further crop production. By tapping reservoirs of fossil water deep beneath the desert, humans are, in effect, mining water. Once this water is gone, it is irreplaceable. Burning and overgrazing of semiarid lands on the periphery of deserts can irreversibly damage the plants that concentrate moisture and hold the soil together, thus enabling deserts to encroach on arable land. This encroachment, a serious world problem, is called desertification. A 1984 report of a desertification study made for the United Nations stated that 35 percent of the earth’s land surface was at least threatened by such processes."
5. What are the causes of the process of desertification?
Information: Burning and overgrazing of semiarid lands on the periphery of deserts can irreversibly damage the plants that concentrate moisture and hold the soil together, thus enabling deserts to encroach on arable land.
What is the cause of desertification? Burning and overgrazing of semi-mountain lands on the periphery of deserts / Water supplied from rivers or wells has ceased. / The plants that gather moisture and hold the soil together are damaged, so deserts can encroach on arable land.