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。
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. )
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.