Question

A microscope is a useful instrument for observing small objects. By producing a bigger image, the microscope reveals details that are undetectable to the naked eye(裸眼).

Before using the microscope, please read the instructions below.

CAUTION: Microscopes are both delicate and expensive and must be handled with care.

1. Always carry the microscope with two hands — one supporting the base and the other on the arm.

2. Avoid stretching the wire of the lamp across a walkway.

3. Keep the stage clean and always use a glass slide for specimens(样本).

4. To avoid crushing the glass slide when focusing, begin with the lens close to the specimen and gradually back off to focus.

5. Keep the microscope covered to prevent the dust while it is being stored.

HOW TO USE THE MICROSCOPE:

1. Plug(接通电源) in the lamp.

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

3. Adjust the mirror so it reflects light from the room up into the objective lens. When the mirror is correctly adjusted, a complete circle of light iwll appear when you look through the eyepiece.

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

5. With the LOW POWER objective leans placed over the slide, use the coarse focus knob 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 teh focus is relatively clear.

7. Use the fine focus knob to fine -tune(微调)the focus.

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.

1.Which of the following is the correct way to use a microscope according to the text?

A．Use one hand to carry the microscope

B．Place a sample directly on the clean stage

C．When stored, the microscope should be adjusted.

D．Look through the eyepiece with one eye.

2.If you want to observe a thin piece of hair, which of the following should you do first.?

A．Switch to objective lens.                  B．Adjust the mirror.

C．Look through the eyepiece.               D．Place the hair on a glass slide.

3.According to the text, you could see a complete circle of light _____.

A．after correctly adjusting the mirror

B．while looking at the specimen on a glass slide

C．after slowly raising the objective lens

D．before positioning the mirror correctly

 

Answer 1

【答案】

1.D

2.D

3.A

【解析】

试题分析：本文主要介绍了显微镜的使用注意事项以及具体如何使用的方法。

1.D 细节题。根据第6点Look through the eyepiece with one eye while closing the other eye. Slowly raise the lens until teh focus is relatively clear.说明要用单眼来观察，故D正确。

2.D 细节题。根据第2点Place a sample of what you wish to observe on a slide说明D正确。

3.A 细节题。根据第3点Adjust the mirror so it reflects light from the room up into the objective lens. When the mirror is correctly adjusted, a complete circle of light iwll appear when you look through the eyepiece.说明调整镜子以后就可以看见了一个完整的圆圈了，故A正确。

考点：考查科普类短文阅读

点评：本文主要介绍了显微镜的使用注意事项以及具体如何使用的方法。本文属于科普类短文，此类文章的最大的障碍是词汇以及考生对阅读内容的不熟悉，需要考生在阅读的时候有足够的耐心。要养成在上下文串联中猜测词义的能力，根据上下文中出现的同义词，近义词，反义词，以及词义的解释来理解生词。同时要抓住文章的中心，不要受其他信息的影响。要根据题目及选项以及文章的上下文串联合理的判断推理。