Please answer correctly the following question related to the paragraph below. Which river had a food source mostly derived from the trees? Two rivers spring from the same mountain. Olt was a fast moving river, while Mures river was slow moving and deep. Both rivers are very important for the local economies. Hint: The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools. These distinctions form the basis for the division of rivers into upland and lowland rivers. The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species. A dam produces negative effects that continue down the watershed. The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of sediment, which leads to loss of deltaic wetlands.
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Answer: Olt

Please answer correctly the following question related to the paragraph below. Which student read less about liver cancer? Two medical students had to study about viruses that cause cancers in humans. Brady studied about hepatitis viruses, while Dean studied about human papillomaviruses and Herpesviridae. Hint: Hepatitis viruses can develop into a chronic viral infection that leads to liver cancer. Infection by human T-lymphotropic virus can lead to tropical spastic paraparesis and adult T-cell leukaemia. Human papillomaviruses are an established cause of cancers of cervix, skin, anus, and penis. Within the Herpesviridae, Kaposi's sarcoma-associated herpesvirus causes Kaposi's sarcoma and body-cavity lymphoma, and EpsteinBarr virus causes Burkitt's lymphoma, Hodgkin's lymphoma, B lymphoproliferative disorder, and nasopharyngeal carcinoma. Merkel cell polyomavirus closely related to SV40 and mouse polyomaviruses that have been used as animal models for cancer viruses for over 50 years.
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Answer: Dean

Please answer correctly the following question related to the paragraph below. Who will have less algae in their lake? Lucy and Sarah are two people who each own a lake that they enjoy spending time at. They have to take care of the lake though and make sure everything is healthy so that the lake can continue to thrive and people will want to visit it. Sarah says she heard a secret that if you dump fertilizer into your lake, the fish will grow twice as large. Sarah says she has just started doing it this past week and can't wait to see the results. Lucy is skeptical and waits to see what happens at Sarah's lake. Hint: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick.
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Answer:
Lucy