Unit 3 Conservation Lesson 1 The Sixth Extinction Grammar 课件-2023-2024学年高二英语北师大版（2019）选择性必修第一册

Unit 3 Lesson 1 The Sixth Extinction Grammar 新 课 导 入 观察下列两组句子。 This is the house which we bought last month. The house, which we bought last month, is very nice. He likes to read books which are written by foreign writers. These apple trees, which I planted three years ago, have not any fruit. 课 堂 学 习 Relative Clause 定语从句 Defining relative clause 限制性定语从句 Non-defining relative clause 非限制性定语从句 1. 限制性定语从句 从句必不可少，否则先行词的意思不明确，主句也不完整，与先行词之间不用逗号。 例句： Mary is a girl who has long hair. I’d like to see the films that are just on show. 2. 非限制性定语从句 对先行词起补充说明或描绘作用，没有它不会影响先行词或主句意思的完整性。从句一般用逗号同主句分开。 例句： George, who is my classmate, has won a scholarship. Lucy, whose father is a fencer, is enthusiastic about sport. 3.限制性定语从句和非限制性定语从句的区别。 限制性定语从句 非限制性定语从句 1. 从句与先行词的关系 对先行词起修饰作用 对先行词起补充说明作用 2. 标点 从句和主句之间不用逗号分开 从句和主句之间通常用逗号分开 3.关系代词 指人who(that), whom; 指物which(that);人和物whose关系代词在从句中作宾语可以省略 指人who(作主语), whom(作宾语);指物which;人和物whose关系代词一般不可省略 4.修饰 从句只修饰名词或代词 从句可以修饰名词或代词也可以修饰整个句子 限制性定语从句 非限制性定语从句 随堂练 1. He has two sons, ______ work in the company. 2. The man ______ is walking in the playground is my old friend. 3. There is no simple answer, _____ is often the case in science. 4. Do you know the reason ______ he was absent? who who as why Read the sentences and discuss which word(s) the clauses (in italics) refer to. 8 1. Extinctions, where entire species are wiped out, are not unusual in our Earth’s history. ( ) 2. These include the third mass extinction, known as the “Great Dying”, which killed 90% to 96% of all species. ( ) refers to extinctions refers to “Great Dying” 3. A 2015 study by scientists who were based at Brown University and Duke University in the US, looked at how quickly species die out due to natural causes. ( ) 4. If a sixth mass extinction occurs, scientists who have studied the issue believe that up to three quarters of all species on E