全新版大英听说4UNIT 4

Unit 4 Explaining Processes

Part A Part B Part C Part D Part E

Pre-listening task How to use an OHP How to send an e-mail Layout of a letter Additional listening task

投影机的灯泡是耗材，按照一般使用频率足够正常使用3年以上， 但是如果操作不当，可以在很短的时间内就会被损坏，而且一只灯 泡的价格也是不菲，可能会达到几千元。为了保护灯泡，减少损 失，用户千万不要随便把不同品牌投影机的灯泡互换使用，这样很 容易由于功率不匹配的原因造成投影机灯泡的报废。 投影机内部有许多光学设备，这些光学设备对其流经的电流大小有 严格的限制，一旦出现电流不稳定或者有较大冲击电流时，很容易 会损坏。为了避免这些设备的受损，建议大家不要频繁开关投影 机，因为投影机在每次开关时，都会产生很大的冲击电流，而投影 机内部的光学器件在多次受到冲击电流的撞击后，寿命会大大缩 短，所以请大家记住，在关闭投影机后如果要重新开机，就必须再 等5分钟以上才可以。

Unit 4 Explaining Processes

What Makes an OHP?1. mirror反光镜，反射境

head (lamp) 投射式前照灯 3. lens透镜，镜头 4. mast 支撑杆 5. focus knob调焦旋钮 6. stage glass投影台 7. base基础, 底座 8. power switch 电源开关 9. power cord电源线2. projection

投影仪的使用1.打开投影柜，轻放柜盖。使投影仪和银幕的距离保持在1.5—2米。在确定 所有操作开关处于关闭状态后，接通电源。 2.掰住支撑杆托架(卡子),扶着支撑杆推至于投影面垂直，此时会有“卡 它”声，表明支撑杆已经到位。注意动作不能猛烈。 3. 打开反射镜盖轻轻开至最大的角度。动作太大就会损坏投影盖，导致投影 仪无法使用。 4. 打开电源开关，此时灯泡应点亮，风扇应转动(用手在投影仪出风口感觉 出风情况或听声音来判断),如风扇不转，应该立即关闭电源停止使用。 5. 调整反射镜、调焦旋钮、色边调整旋钮，最终在银幕上得到清晰的白色亮 面。 6. 在投影台上放置投影片，调整调焦旋钮，使银幕图象清晰。(使用带药面 的投影片时，应使药膜面朝上) 7. 使用完毕后关闭电源开关。一手扶住支撑杆，一手扒起支撑杆插销，然后 慢慢放下支撑杆至支撑杆托架(卡子)上固定。 8.盖好防尘罩，把电源线收至柜内，关好门。 注：要严格投影仪使用步骤，注意规范操作。

Exercise1Step 1. Put the OHP on the table. Step 2. Press the buttons in and lift this part up until it snaps into place. Step 3. Turn the OHP round so the head is facing towards the screen or a white wall. Step 4. Plug it in. Step 5. Switch it on. Step 6. Place the transparency on the stage. Step 7. Move the flap up or down to raise or lower the image. Step 8. Turn t

he wheel to make the image sharp.

Exercise 21.

2.3.

Place the OHP about 2 meters from wall or screen. A screen works better than a wall. Leave the OPH switched on when using it and place a piece of paper over the glass.

Study focus:

This unit aims to present and practise English as it is used both in the explanation of modern everyday machines and the processes they carry out.

Pre-listening task (P36-37)Questions for discussion:1. Can you explain to someone in simple English how to operate a machine (say, an OHP) or perform a task? 2. What difficulties would you have in explaining the procedure for operating modern office equipment (computer, for example) in English? 3. How can we make our presentation more effective?

What makes an OHP? (P37)1. 2.

3. 4. 5. 6.

7.8.

Mirror反光镜，反射 境 Projection head (lamp) 投射式前照 灯 Lens透镜，镜头 Mast 支撑杆 Focus knob调焦旋 钮 Stage glass投影台 Base基础, 底座 Power switch 电源

Expressions used when explaining a procedure: To

explain the order in which certain things are done:– First of all… – The next thing you have to do is… – And then finally…

To add a further point: – Make sure you… – Oh, and by the way, don’t forget to… – Oh, and be careful not to…

To

check that the other person is following you, or has understood:– OK, so is that clear? – Does that seem to make sense? – So there we are. Do you have any questions?

If

you want to ask someone to explain something to you, you can say:– Excuse me, could you show me how to…? – I wonder if you could tell me how this works?

If

you haven’t understood the explanation, or if you can’t follow the instructions, or if you want to check that you’ve understood so far, you can say:– I’m sorry, I didn’t quite follow you there. – I’m sorry, what did you say that part was called?

When

you think you’ve understood, you can say:– If I’ve understood right… – So is the basic idea that…? – You mean…