教材分析：本单元涉及的话题是全球变暖，在话题及语篇主题的引领下，使学生探究人类命运共同体的诸多问题——人类活动引起全球变暖(能源的使用问题/环境的保护问题），全球变暖带来了那些后果?我们又怎样看待全球变暖这一问题。地球作为我们人类的母亲，我们又如何来保护它?这些都是我们本单元应该深度思考的问题。
思维导图：
Human beings' activities
(Using all kinds of energies/damage to environment)
↓
global warming
↓
bad effects good effects
↓ ↓
disaster (plants grow
↓ quickly）
(rise high the level of sea） (products
(storms/floods/droughts/ more）
famines） human beings' (disappearance of species) life better
human beings' activities→carbon dioxide→greenhouse gases →greenhouse effects → global warming
How to protect our earth→ save energy /reduce pollution/recycle something/plant more trees→advertise the knowledge of protecting environment→raise awareness of public→cooperation → our earth (better)
Facing to these problems,only by working together will we make the situation better and better.
(面对诸多问题，我们只有共同努力，情况才会变得越来越好)
