Упр.2b Уроки 3-4 Юнит 6 New Millennium English 11 класс
Приведем выдержку из задания из учебника Казырбаева, Дворецкая 11 класс, Титул: 2 B. Read the introductory chapter from the textbook Biology for Life and see if you can finish Ex. 2A. Whatever branch a scientist is interested in, he observes things and asks questions about them. What is that structure for? How does it work? Why is the animal behaving like this? Why are weeds growing here but not there? Testing hypotheses Suppose we want to know why a certain type of plant grows well in place A but badly in place B. The first thing to do is to put forward a possible reason. Scientists call this a hypothesis. The next step is to test this hypothesis to find out if it is true or not. This is done by carrying out an experiment. Scientists often investigate things by first thinking of a hypothesis, and then testing it by observing things or by doing experiments. This procedure is sometimes called the scientific method. Doing experiments Suppose we want to test the hypothesis that light is needed for the leaves of a young plant to become green. We obtain a plant and put it in the dark. If the green colour fails to develop, we will conclude that light is needed for it. However there is something more that we must do: we must obtain a second plant and put it in the light. We need this second plant in order to provide a standard with which to compare the first plant. The second plant is called the control. In carrying out experiments it is essential that the two plants should be kept in exactly the same conditions, except for the light they receive. To put it in a general way: we keep all the variables constant except for the one whose effect we want to investigate. An experiment of this kind, in which the experimenter controls the conditions, is called a controlled experiment. *Цитирирование части задания со ссылкой на учебник производится исключительно в учебных целях для лучшего понимания разбора решения задания.
Scientists observe things and ask questions about them. They put forward a possible reason, called a hypothesis, and then test it by carrying out an experiment. This procedure is called the scientific method.
To test the hypothesis that light is needed for the leaves of a young plant to become green, scientists put one plant in the dark and another one in the light. The plant in the light is the control, because it provides a standard for comparison. In a controlled experiment, all the variables are kept constant except for the one being investigated.
