The exercises are more or less finished.

作业 快要做完了。

15. Children under 1.2m in height can not be taken into the concert hall.

1.2米以下的孩子禁止带入会场。

height 为名词，形容词为high. 1.2 m in height 意为 1.2m high。如：

— What is his height?

— He is six feet in height (=He is six feet high.)

— 他有多高?

— 他有六英尺高。

关于含有情态动词的被动语态的讲解

※含有情态动词的被动语态的构成

前两个单元已学过一般现在时态和一般过去时态的被动语态的构成，以及被动语态的用法。本单元学习含有情态动词的被动语态。它的构成形式是：情态动词+ be + 动词的过去分词;否定式是在情态动词后 + not, 疑问式是将情态动词放于主语之前。情态动词有：can, may, must, school, could, have to等。例如：We must find out the truth . → The truth must be found out .

(1)The trees must be planted in spring.

树必须春天栽。

(2)May the exercises be done tomorrow?

练习可以明天做吗?

(3)Books can not be taken out of the reading-room.

书不能带出阅览室。

(4)These young trees should be watered every day.

这些小树应每天浇水。

(5)The sick person need be taken good care of.

那病人需要很好地照顾。

(6)Your bike has to be mended well.

你的自行车需好好修修了。

※ 被动语态与系表结构的区别

动词 be + 过去分词这个结构并不定都是被动语态结构，有时它可能是 be + 过去分词 ( 作表语 ) 的系表结构。因此：

be + 过去分词 ( 被动语态 ) 与 be + 过去分词 ( 作表语 ) 这两种结构的主要差别是：

①被动结构表示一个动作，带表语的结构表示主语的特点或所处的状态。如：

The library is now closed . ( 系表结构 )

It is usually closed at 6 . ( 被动结构 )

②被动结构后面可带 by + 实施动作者，而系表结构一般没有。如：

The glass is broken . ( 系表结构 )

It was broken by my sister . ( 被动结构 )

③“系表结构”中的过去分词可以被 well , very 等副词修饰，而“被动结构”中的过去分词则一般不能如此。如：

The book is well written . ( 系表结构 )

The book is written 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/Im 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, Whats 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 dont dig the hole too deep/the hole should not be too deep.

B: OK. Ive dug a hole. It’s just right.

2. A: Good. Thats 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: Whats next?

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

B: OK. Ive done that.

A: Right. Ill put the earth back in the hole again while you hold the tree straight. Then, lets 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 youre doing that, Ill go and get some water.

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

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

(Certainly. Lets 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。

Whats 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 sentence)。然后对文章进行段落的划分。然后让学生归纳出每个段落的大意。

课文的段落划分和主题句或大意如下：

第一段：第l自然段

主题句：Forests help to keep water from running away.

第一段大意：The importance of forests;

第二段：第2—3自然段

主题句：Chinese people have built a new Great Wall.

第二段大意：Something about the Great Wall in China

第三段：第 4—6自然段

主题句：The more trees there are, the better harvests we have.

第三段大意：Something about a worker, who works on the Green Great Wall, thinks highly about the Green Great Wall.

教师还可以让学生填写下表：

THE GREAT GREEN WALL

Special features

across the northern part of China，7，0OO kilometres long，between

400 and l700 kilometres wide

Functions

It stops the wind from blowing the earth away; and stops the sand from moving toward the rich farmland in the south. It has saved a lot of land.

Wang Feng and other workers

They work at Yulin in Shaanxi. They have planted ten thousand tree this year. It’s difficult to work on the Great Green Wall. They have to grow their own food.

提取主题词(key words)也有助于帮助学生复述课文大意。

Forests

keep from, water, soil, floods

China

copy, across, is…long and between…and …wide, stop…from, save, needed, all over the world

Wang Feng

work on…, visit, among, ask, plant, over there, on the hill, five years ago, in a few years’ time, be covered, point to, difficult, grow food, thanks to

在进行写作训练时，可以要求学生仿照课文，写一篇以How to plant flowers in the garden 为题目作文。

关于带情态动词的被动语态的教学建议

本单元在前两个单元学习一般现在时和一般过去时的被动语态的基础上，继续学习带情态动词的被动语态。

在第41课，以显著的位置展示题为“HOW TO PLANT A TREE”的操作规程(instructions)，教师如果仅仅是按部就班地讲解，就会使学生感到枯燥乏味。要充分利用课文中所提供的情景，在有意义的情景中教学语法知识。例如，教师可利用简笔画来引出新的语法知识。学生基本掌握instructions大意后，教师应引导他们理解情态动词的用法。到了第43课可采用对比的方法。教师列出两个框框，要求学生分别填上课文中已出现的带情态动词的句子，和可以由主动语态变为情态动词的被动语态的句子，把变化后的句子填入框内。如下表：

1. The ground must be just right.

2. But the hole should not be too deep.

1. The earth should be neither too wet nor too dry.

2. A hole must be dug large enough for the tree. The size of the hole must be just right.

3. A long, strong stick should be knocked into the earth next to the hole. It must be firmly planted.

4. The tree must be put in the hole so that it is straight. The tree must stand straight in the hole.

5. The earth must be put back in the hole again.

6. The earth should be pushed down hard with ....

7. The tree must be tied to the top of the stick ....

8. It should be watered well, ....

学生在做这个练习时，对本课句型与词汇有了进一步认识，同时也锻炼了写的能力。

在有条件的学校可放教学录相以加深印象。在全班读熟课文后，展示几幅植树的图片，让学生独自准备几分钟，进行连锁练习，按次序复述instructions。也可两组之间进行比赛，由A组说出第一条注意事项，再由B组说出下一条。最初可完全复述课文原句。熟练后，可全部用主动语态或全部用被动语态，或一句主动语态一句被动语态交替出现，或句子中带有情态动词等方式进行操练。