Title 3 read-1.docx ✅

TEST 1 Part I: Read the following passage and choose the best answer. Write your answers in the corresponding numbered boxes. (15pts) EUTROPHICATION All plants need nutrients, but an excess or nutrients can be lethal to the ecosystem. Water bodies such as lakes or estuaries naturally have certain amounts of nutrients, and are rich in species. Species-rich ecosystems have a high level of biodiversity. However, when chemical nutrients infiltrate water in marine habitats, the plants will begin to grow without restraint and then decay rapidly. This process, known as eutrophication, can disturb the ecological balance and eventually result in severe reductions in water quality. Inspections of lakes and reservoirs around the world demonstrate that 54% of lakes in Asia are eutrophic; 53% in Europe; 48% in North America; and 28% in Africa. Today, eutrophication or what some call nutrient pollution is the number one water quality problem around the world. In the 1950s, eutrophication was acknowledged as a waste problem in several lakes 3% Europe and North America although it was not immediately clear what the causes were. It had taken place over a short period of time in these lakes, and this shocked scientists because eutrophication had normally been known as a natural process that develops over thousands of years as a lake or river becomes older. Scientists, who observed the excessive growth of plants and algae, often called an algal bloom, studied the phenomenon intensely from the 1960s to the 1970s. Their research pointed to the presence of large amounts of plant nutrients, including phosphorus, nitrogen and carbon, which are vital for life in the river and sea. The nutrients were traced to human activities: runoff from livestock waste, the release of domestic sewage and industrial wastewater. Moreover, in some ecosystems, nutrients had been deliberately added for purposes of enrichment. The large amounts of nutrients accumulated and their compounds acted as a stimulant to uncontrolled phytoplankton growth. The unlimited growth of phytoplankton species provokes profound changes in the lake or river. Marine plants and plant particles breathe out oxygen during photosynthesis. When eutrophication occurs, however, the excessive amount of phytoplankton species spread over the surface of waters and block the sunlight, so the marine plants are not able to photosynthesize, then the amount of oxygen is reduced. When the dead plants and animals are decomposed , oxygen is consumed, therefore the dissolved oxygen is also reduced greatly. The lack of oxygen causes many organisms to suffocate and numbers of dead fish begin to appear in the water, and more animal species die out.
The water loses its transparency, sometimes changing into a murky brown, red or orange color, and this phenomenon is called “red tide”. If the oxygen becomes completely depleted, bacteria called Clostridium botulinum becomes abundant and causes botulism, a disease of the nervous system that is often fatal. The bacteria poisons and kills birds and mammals that eat any existing phytoplankton in the water body. With so much death taking place, scientists call anaerobic waters “dead zones”. Ultimately, these effects have an impact on human beings. The swift eutrophication in Lake Erie, one of the Great Lakes, was the subject of much concern and instigated experimental research. In 1968, the Experimental Lakes Area (ELA) was established as a field station and had been added various nutrients to determine which combination of nutrients was the key to controlling eutrophication. [A] The most interesting experiment was a lake that was divided into two with a plastic curtain. One half was left alone while the other half was divided into three parts and each fed carbon, nitrogen and phosphorus. [B] The lake was monitored for 8 years, and it was observed that the portion receiving phosphorus had eutrophic algal blooms. The parts containing carbon and nitrogen did not have those. [C] The American government has since earmarked billions of dollars for a phosphate control program. [D] 1. The word “infiltrate” in the passage is closest in meaning to _____. A. stimulate B. penetrate C. operate D. aggravate 2. In paragraph 1, what does the author say about the global incidence of eutrophication? A. A majority of the lakes on earth are eutrophic and cause a big water problem. B. The worst incidence of eutrophication is in lakes in Asia and it results in social problems. C. Africa has fewer eutrophic lakes because there are not many water bodies. D. Lakes in Asia are showing the fastest rate of lake eutrophication. 3. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect answer choices change the meaning in important ways or leave out essential information. A. Scientists concluded in the 1950s that wastes from human activity were causing eutrophication in lakes. B. People in Europe and North America ' knew that eutrophication was the most serious environmental pollution. but they did not understand why it was happening.
C. It was not known right away what caused eutrophication in European and North American lakes, but by the 19503, it was accepted as an environmental problem. D. Lakes in Europe and North America were exhibiting waste problems in the 1950s. 4. Which of the following can be inferred about the process of eutrophication? A. It has largely been an intentional process. B. It has been accelerated because of humans. C. It is exacerbated by the presence of phytoplankton. D. It is impossible to stop once it is started. 5. All of the following are mentioned in the passage as contributing to eutrophication EXCEPT _____. A. wastewater from cleaning activities B. excess water from farming regions D. garbage that is not properly subjected to treatment D. plants growing excessively at human residences 6. The author cites the presence of huge amounts of phytoplankton in a lake as _____. A. a sign that the lake will sustain a number of negative changes B. an indication that the lake has a sufficient amount of nutrients C. evidence that birds and animals are not eating marine plants D. a warning that the water is not fit for human consumption 7. Which of the following dangers arises when there is no oxygen in a lake? A. An increase in carbon dioxide B. The production of a toxic germ C. Too much of phytoplankton
D. Accelerating the decomposition of living things 8. It is stated in the passage that _____. A. humans have overused the lake B. if the water changes its color, it means there is no organism living in it C. Clostridium botulinum usually has adverse effects, but can be favorable sometimes D. botulism exerts a bad influence on the nerves in our body 9. The author discusses the work at the ELA in the passage in order to _____. A. describe the ongoing research on what factors may be causing lakes around the world to die B. determine the best techniques for conducting research on lakes C. illustrate how researchers discovered what caused eutrophication D. compare the findings that the ELA has made with those of the United States government 10. Look at the four positions [A], [B], [C] and [D] that indicate where the following sentence could be added to the passage. Thus, through these experiments, the ELA, concluded that phosphorus is the key nutrient that needed to be controlled. Where would the sentence best fit? A. [A] ` B. [B] C. [C] D. [D] Your answer: 1 2. 3. 4. 5. 6. 7. 8. 9. 10.