YÖKDİL Fen - 2021 Ağustos (Soru 31-41)

ONLINE Sınav Analizi 31. Fossil fuels, which is a major source of pollution, cannot be replaced when their limited supplies are used up, —. A) while renewable energy sources will not run out and produce little pollution B) as long as the sun shines, winds blow, waves crash and rivers flow C) though coal, oil and gas are the most important fossil fuels D) so that the wind can be used to spin turbines to generate electricity E) if windmills have been used to power machines for many centuries 32. ----, whereas decay of organic material releases it back to the atmosphere. A) Soil bacteria and other biological agents remove nitrogen from the atmosphere B) Water vapour is known to be an extremely important gas in the atmosphere C) The upper parts of the atmosphere contain a large number of ions D) Nitrous oxide is being produced at an unprecedented rate due to exhaust fumes E) A chemical difference in the composition of lighter gases can occur as they rise 33. Although the majority of reflexes are innate responses, ----. A) a reflex is known to be a response to a stimulus across multiple systems B) the human body has numerous essential reflexes like swallowing C) others are conditioned into a person as a result of life experiences D) the diving response is a breathing reflex triggered by submergence E) a new-born's reflexes are primitive ones present in the first few months of life 34. Although one-humped and two humped camels are given separate species names, —. A) both male and female camels have the same number of teeth for feeding B) they originally spread into South America, Asia, and Africa from North America C) they can interbreed fairly easily and are probably varieties of a single species D) the most common camel is known as the one-humped Arabian or dromedary camel E) they are central to the survival and culture of the nomadic peoples of the old-world deserts 35. Taking regular doses of vitamin C will not protect us from catching a cold; ----. A) likewise, easing its symptoms is one of the functions of the immune system B) consequently, over-the-counter drugs treat only the symptoms of cold C) hence, antibiotics such as penicillin are useless against the common cold D) in short vitamin C is one of the major antioxidants helping to heal wounds E) however, high doses of vitamin C may help to alleviate symptoms of cold 36. Even though birds have different structures for tear production compared to humankind, ----. A) tear production takes more time in humans and is a more complicated process B) tears of some species, including owls, contain higher levels of protein C) some components of their tears are present at similar concentrations found in humans D) maintaining eye health that is necessary for hunting is of great importance for birds E) researchers have enormous difficulty in collecting tears from certain bird species 37. Contrary to popular belief, the Earth's seasons are not caused by the varying distance from the Sun ----. A) as our planet's tilt causes the intensity of the sunlight to change over the Earth at different times B) so the Earth's orbit has a point at which it is closest to the Sun and another at which it is farthest from it C) but they occur because of the tilt of our planet's axis in relation to the plane of the Sun D) although the Earth does not spin around the Sun in a perfect circle but follows an elliptical orbit E) because when the North Pole is tilted towards the Sun, it is summer in the Northern Hemisphere 38. The African continent is poor in limestone outcrops in general, ----. A) yet no remarkable caves have developed due to the desert climate B) but its northern zone, Algeria in particular, has abundant sources of it C) so these formations are large reservoirs sustaining the base flow of many rivers D) whereas there is little potential for remarkable discoveries in some African countries E) for instance, for a long time Morocco had the continent s longest cave networks 39. ----, those that occur can be catastrophic events involving a great loss of life. A) Although airline accidents occur infrequently B) Because recent aviation accident rates are very low C) If bad weather alone does not cause an accident D) As the reasons for approach and landing accidents vary E) Since the first consideration is to assist the injured in case of an accident 40. The moulds that grow indoors can be of particular concern for humans ----. A) as long as the mould varieties used in cheese production are sterilised B) even if the types of mould growing on food are believed to cause cancer C) unless some of the products of mould metabolism have great importance D) even though almost all sorts of mould require a moist surface for growth E) because they can cause allergic reactions in those who are sensitive 41. Atmospheric chemistry is a very complex science, ---- A) as the composition of the atmosphere is in constant instability