Guarding nature (P2) 吉林毓文中学  赵传彦 
I. Lead-in  “Variety is the spice (趣味) of life. But not when it puts the natural ecosystem in danger.” How do you understand this sentence?  

II. Skimming  Read the text quickly and find what the text mainly talks about. It is a brief introduction to China’s first biosecurity law.  
Let’s learn about the structure of the text.  

III. Read and explore Read the text carefully and answer the following questions. 1. What areas will China's first biosecurity law have a great effect on?    

2. Why was the law issued? What are the problems facing China? China is one of the countries that suffers the most from the invasion of alien species! Para 4-6 
3. What methods did the author use to describe the biosecurity risks facing China?  

Although bioinvasion can happen naturally, it is more often a result of human activity. 
4. How can the bioinvasion issue be resolved?   

Pathways of invasion   

IV. Language study 如果说英语单词的前后缀（Prefix /Suffix ）像汉语的“偏旁”，那么词根（Root）就似“部首”，一个单词核心表义由词根统领，辅以前后缀以改变词性、词义。学习词根就是学习“见字识意”，能将背单词转化为理解单词，增加趣味，提高效率。 单词通常由 3 部分组成： 前缀（prefix） 词根（root） 后缀（suffix） 前缀和后缀，可以改变单词的意思  eco=生态的；经济的 ecology=eco生态+logy...学            生态学 economy=eco经济+nomy...学          经济学 ecosystem=eco生态+system系统          生态系统 ecotourism=eco生态+tourism旅游      生态旅游 bio=生命的、生物的 biosecurity=bio+security          生命安全 biotechnology=bio+technology    生物技术 biodiversity=bio+diversity        生物多样性 bioinvasion=bio+invasion        生物入侵 biosafety=bio+safety            生物安全  V. Culture anecdote    
Crayfish is an invasive species from the United States, but it has become a popular food in China.
Crayfish burrowed(打洞) in the terraces（梯田, causing the collapse of Hani terraces, a world cultural heritage site. The yield of rice decreased and the landscape was damaged. The local government has to spend 1.1 million yuan a year to buy pesticides (农药) to reduce crayfish.