2016新课标创新人教英语 必修五 Unit 4 Section 5(4)

2．Place a sample of what you wish to observe on a slide.

3．Move the mirror so it reflects (反射) light from the room up into the objective lens. When the mirror is in the correct position, a complete circle of light will appear when you look through the eyepiece.

4．Place your slide with the sample directly over the center of the glass circle on the stage. If it is a wet slide, be sure the bottom of the slide is dry.

5．With the LOW POWER objective lens placed over the slide, use the coarse focus knob (粗聚焦旋钮) to lower the lens to the lowest point.

6．Look through the eyepiece with one eye while closing the other eye. Slowly raise the lens until the focus is relatively clear.

7．Use the fine focus knob (精细聚焦旋钮)．

8．Without changing the focus knobs, switch to the HIGH POWER objective lens. Once you have switched to HIGH POWER, use only the fine focus knob to make the image sharper.

语篇解读：本文是应用文。文章主要介绍了如何使用显微镜以及注意事项。 1．If you want to observe a piece of hair, which of the following should you do first? A．Move the mirror. B．Cover the microscope. C．Look through the eyepiece. D．Place the hair on a glass slide.