Planting trees

ritten by Li Ming . ( 被动结构 )
　　④被动结构可以用于许多时态之是，而系表结构只用于一般现在时和一般过去时这两种时态。如：
　　The work is being done . ( 被动语态 )
　　The work is done . ( 系表结构 )
　　⑤系表结构有主动意义，而被动结构只有被动意义。被动结构的句子往往有表示动作的时间、地点、方式、目的等状语，而系表结构一般没有这样的状语。如：
　　The photo was taken last month . ( 被动语态 )
　　The photo was well taken . ( 系表结构 )

本单元的有关听说读写的教学建议

　　◆有关听说方面的教学建议

　　本单元第41课以Read and act的形式来引出本课的教学重点。教师应充分利用这个对话情景，进行对话表演，以提高学生的兴趣，达到自然地呈现新课的目的。

　　教师在上课时，可穿一件旧衣服或工作服，问学生，“I came to school in/I'm wearing my old clothes today. Tomorrow you will come to school in your old clothes. Do you know why?” 这时，学生们可以进行多种猜测。在学生情绪高涨时，教师让他们带着问题听课文录音。在听第一遍录音后，利用本课挂图，再让学生听一至两遍录音。为了帮助他们更好地理解对话的内容和句型，教师此时可将一些关键词写在黑板上，如：: in old clothes, What's happening? Tree Planting Day, Really? Wonderful! 在学生了解了对话的基本内容后，教师可放录音让全班跟读或分角色对话。然后两人一组借助黑板上的关键词来复述或表演。注意这段对话的主要目的是引出下面的“instructions”，而且对话中新的语言知识不多，所以不必占用过多的时间。

　　在进行了一定的pair work 之后，教师可以要求学生进行表演练习。出示关于植树过程的一组图，让学生回忆植树的经过和步骤，在教师的引导之下，用英语将这些步骤表达出来。

　　如：How to choose the ground?

　　What should we do for the first step? Dig a hole or knock a stick into the earth?

　　What should we do for the second step? Knock a stick into the earth or put the tree into the hole?

　　What should we do next? Put the tree into the hole or put the earth back into the hole?

　　What should we do next then? Push the earth down hard?

　　Tie the tree to the stick or water the tree well. which step comes earlier?

　　通过上述问题的问答，学生就基本上明白了植树的步骤。然后要求学生在小组内进行口头的表达，要求学生能够比较流利的表达植树的过程。

　　第44课在Read and act下也有3段对话。但与第41课对话不同。这时学生已学完本单元的语法重点和阅读文章。这3段对话设计的目的在于巩固学生所学的知识，并提供不同情景引导他们实际应用。教师可设计如下3幅简笔画。

教师可分段放录音或在课前事先安排3位学生与教师配合表演这3段对话。然后进行全班、半班或两人一组的练习。教师分段抽查数组表演情况。在学生已基本能分别表演3段对话的基础上，让他们将3段对话串在一起进行表演，教师可用简笔画或手势、动作来提示学生。

　　最后教师应鼓励学生实际应用所学知识，如让学生根据第41课的 “instructions”，依照第44课的3段对话，自编对话，进行表演。以下4组对话包括了instructions中所有的注意事项，并尽量使用带情态动词的被动语态。如：

　　1. A: Will you help me plant this tree, please?

　　B: Of course/Certainly. What do you want me to do?

A: Well, dig a hole large enough for the tree. But don't dig the hole too deep/the hole    should not be too deep.

　　B: OK. I've dug a hole. It’s just right.

　　2.  A: Good. That's done. Hold this stick while I knock it in.

　　B: OK. Make sure that it is straight.

　　A: Is it straight (now)?

　　B: More or less!

　　3. B: What's next?

　　A: Put the tree in the hole now/The tree must be put in the hole now.

　　B: OK. I've done that.

A: Right. I'll put the earth back in the hole again while you hold the tree straight. Then, let's push the earth down hard with our feet several times.

　　4. B: Good. Now the tree must be tied to the top of the stick to keep it straight.

　　A: OK. While you're doing that, I'll go and get some water.

　　B: OK. But can we go and have a drink after that?

　　A: A drink? We've only just started! There are twenty more trees to be planted.

　　(Certainly. Let's go. But we have twenty more trees to be planted. )

　　◆有关读写方面的教学建议

　　在阅读的教学过程中，一定要重视语篇的教学，也就是说，在教学的过程中，教师不要过分的强调句子的结构或者是过分的强调句子的语法功能分析，而忽略了文章的本来面目。例如，文章的结构，文章的主题句，文章的基本段落的中心意义等。允其要引导学生将文章中的个别句子放在上下文的语境中进行准确理解。在教学本单元阅读课文时，教师首先要让学生了解课文大意，然后帮助学生分段理解，并可划分段落，找出主题句(topic sentence)。在本课结束时，学生应能复述课文。

　　在阅读前，教师可设置如下问题，让学生猜测并讨论，以引起他们的阅读兴趣。

　　What's the Great Green Wall?

　　Where does China build the Great Green Wall?

　　What does the Great Green Wall do?

　　在学生讨论过程中，教师可利用学生用书第III页彩图和教师用书提供的材料 (Notes)，适当给学生们补充一些背景知识 。

　　T: Sanbei shelter-forest (三北防护林) is known as China’s “Great Green Wall”. It is a “Great Green Wall” of trees, millions of trees. China has built a new Great Green Wall across the northern part, including Inner Mongolia, Shanxi, Hebei, Beijing and Tianjin. The Great Green Wall also covers some of the Northwest (Xinjiang, Qinghai, Gansu, Ningxia and Shanxi) and the western part of the Northeast (Liaoning, Jilin and Heilongjiang). It includes altogether 13 provinces, cities and autonomous regions (自治区). Its total area is 4, 069, 000 square kilometres, which cover 42.4% of the land of China. The building of the Great Green Wall will take 73 years (1978—2050). The Great Green Wall has already saved a lot of land by stopping the wind from blowing the earth away and the sand from moving towards the rich farmland in the south. But more “Great Green Walls” are still needed not only in China but all over the world.

　　教师在介绍背景知识时，可借助中国地图、手势等使学生大致了解，必要时可用汉语解释。文中划线句子为课文中原句或对原句稍加改动的句子。教师在讲到这些句子时可适当强调、重复，以加深学生的印象。

　　然后让学生打开书阅读课文。在确知大部分学生已基本掌握课文大意的情况下，要求他们划分课文段落并找出每个段落的主题句 (topic

《Planting trees(第8页)》