参考答案：Teaching plan(one possible version)：
Step 1．
1．Explain the formation of the word and the function of prefixes．
2．Do the exercise to point out which of the following words have negative prefixes．
nonstop unfold incorrect important understand
invite unlucky impossible uniform interesting
3．Matching exercise
un- smoking
non- possible
dis- able
im- like
Answer：unable，nonsmoking，dislike，impossible
4．Blank-filling with the above words(using Restrictive Attributive Clauses for example)
(1)This is a nonsmoking room．You’d better go to the smoking room，which is ten meters on your right．
(2)The boy who was unable to finish his work on time felt a bit sorry for himself．
(3)Tom and Jack are the only ones in their class who dislike football．
(4)It sounds impossible that the little boy who looks so shy in class would be so brave to catch a pickpocket on the bus yesterday．
Step 2．
Give some examples of Restrictive Attributive Clauses and Non-restrictive Attributive Clauses．
1．Let students distinguish which of the following sentences are Restrictive Attributive Clauses and Non-restrictive Attributive Clauses．
Non-restrictive：
Lijiang，where I was born，is beautiful．
John，who speaks Spanish，works there．
Restrictive：
The village where I was born is beautiful．
People who speak Spanish work there．
2．Explain the differences between the aforesaid two clauses．