Unit 5 Understanding ideas (2)课件 2025-2026学年外研版英语八年级下册

Looking into nature Unit 5 英语外研版八年级下册 Understanding ideas (2) 通过本课时的学习，学生能够： 1. 正确理解宾语从句的概念，在语境中归纳总结引导词that，if/whether的用法； 2. 准确使用that，if/whether引导的宾语从句； 3. 增强对自然探索的兴趣。 重点 重点 Learning objectives 名词 I like apples. I can't find him. Lucy finished doing her homework. Lili wants to go fishing. I think that we shall become good friends. 代词 doing to do 句子 宾语从句 放在动词后面作宾语的句子，我们称为宾语从句。 Read and find Find out the objects in the following sentences. Read the sentences and translate them. Pay attention to the words in red. (a) For hundreds of years, people believed that dinosaurs looked like huge lizards. (b) They can tell us whether dinosaurs had feathers, but that's not all. 跟在及物动词后面 作宾语 Read and translate that, if/whether引导的宾语从句 Now find more sentences with these structures in the reading passage. However, thanks to a piece of amber, scientists now know that this idea is wrong. They also help us understand that life on earth has always changed. But the find proves that it did 35 million years ago. In the future, amber may also help us discover if other species have changed over time. Read and find Research shows that they are a completely new species. Scientists used to believe that ants came from the northern half of the earth. Who knows whether this piece of amber will tell us more secrets? People believed that dinosaurs looked like huge lizards. Scientists now know that this idea is wrong. They also help us understand that life on earth has always changed. Research shows that they are a completely new species. 主句（主语+谓语） + 引导词 that + 从句（主语+谓语+其他） Read and think They can tell us whether dinosaurs had feathers. Who knows whether this piece of amber will tell us more secrets? Amber may also help us discover if other species have changed over. 主句（主语+谓语） + 引导词 if/whether + 从句（主语+谓语+其他） Read and think that引导的宾语从句 当宾语从句的谓语动词表示肯定的概念，用来陈述一个事实、观点或情况（也就是陈述句）时，一般用that引导。 Read and learn that “三无产品” 无意义（没有意思） 无成分（在句子中不做成分） 无存在感（可以省略） whether/if “两有一无” 有意义（有意思） 有存在感（不能省略） 无成分（在句子中不做成分） Read and learn 当主句的谓语动词后面需要接一个“是” 或 “否”的问题时，我们用whether 或 if来引导这个宾语从句。 Observe the sentences and fill in the blanks. 1. I don't know whether/if it will rain tomorrow. 2. I don't know whether he will come or not. 3. It depends on whether he has time. 4. He hasn't decided whether to go or stay. Observe and fill 情况 引导词 1. 与 or not 直接连用 ____________ 2. 介词之后 ____________ 3. 不定式 (to do) 之前 ____________ 只用whether 只用whether 只用whether 陈述语序! 宾语从句使用_______语序：主语+谓语+其他. Observe and fill I hope that you can join us one day. Could I ask if you’ve mentioned this to her? I want to know whether he will come to the party. 陈述 主句的时态是一般现在时，宾语从句的时态可以是________时态。 Observe and fill I know that he lives in Zhejiang. I believe that you are telling the truth. I don't know if there will be a bus any more. 任意 主句：一般现在时 从句：一般现在时 主句：一般现在时 从句：现在进行时 主句：一般现在时 从句：一般将来时 主句的时态是一般过去时，宾语从句的时态是________的某种时态。 当宾语从句所表示的是客观事实、真理时，不管主句用什么时态，从句都用一般现在时。 He told me that the earth goes around the sun. 他告诉我地球绕着太阳转。 Observe and fill She asked if I was hungry. He said (that) he was working hard at that time. 主句：一般过去时 从句：一般过去时 主句：一般过去时 从句：过去进行时 过去 Connect the sentences with that, if or whether. 1. Is there life in outer space? Scientists aren't sure. 2. “I want to be a scientist and study plants," John told his parents. 3. Is Mr Brown interested in insects or birds? Emily wants to know. Scientists aren’t sure if / whether there is life in outer space. John told his parents that he wanted to be a scientist and study plants. Emily wants to know if / whether Mr Brown is interested in insects or birds. Read and connect Complete the messages with that, if or whether. MESSAGE BOARD Hello, I went to your museum today. You missed Pluto in the model of the solar system. There were only eight planets in it. I don't know 1_____________ this is a mistake. if / whether Read and complete Dear Daniel, In the past, people thought 2__________ there were nine planets. However, questions were raised about 3__________ Pluto was a planet. In 2006, scientists agreed 4__________ a true planet: 1. moves around the sun 2. is round (or nearly round) 3. can clear things in its way Pluto doesn't meet the third point. Therefore, we now believe 5_______ there are eight true planets in the solar system. That's why Pluto isn't part of the model. Please let me know 6__________ you need more information. that if / whether that that if / whether Read and complete People's understanding of nature keeps changing. Read the notice Group work. Decide on one discovery and answer the questions. 1. What is the discovery? 2. Who made the discovery? 3. What’s amazing about it? 4. What can you learn from it? →Useful expressions · For hundreds of years, people believed that... · ... made an amazing discovery. · By…., ... found / realised / saw that... · It proves that... · It teaches us that... · Research shows that.. Disucss and answer 1. What is the discovery? 2. Who made the discovery? 3. What’s amazing about it? 4. What can you learn from it? Group work. Decide on one discovery and answer the questions. Discuss and answer For hundreds of years, people believed that...; The discovery of... has changed old beliefs about...; By..., ... found/realised/saw that...; Research shows that... By..., ... found/realised/saw that...; ... made an amazing discovery. It’s amazing that...; What’s amazing is that...; It proves that...; Research shows that...; ... unlock the secrets of nature. It teaches us that...; I can learn that...; We should put more effort into... 1. What is the discovery? Group work. Decide on one discovery and answer the questions. Example By watching and listening carefully, scientists have discovered that whales use these sounds to talk to each other in the ocean. Discuss and answer For hundreds of years, people believed that...; The discovery of... has changed old beliefs about...; By..., ... found / realised / saw that...; Research shows that... 2. Who made the discovery? Group work. Decide on one discovery and answer the questions. Example In the 1960s, a scientist named Roger Payne studied humpback whales. He made an amazing discovery. Their sounds were special repetitive patterns, just like human songs. His research shows that whale songs can travel very far underwater. Whales use these songs to share information, find food and look for friends. Sometimes, many whales sing the same song, and the song can change over time. 3. What’s amazing about it? Discuss and answer By..., ... found / realised / saw that...; ... made an amazing discovery. It’s amazing that...; What’s amazing is that...; It proves that...; Research shows that...; ... unlock the secrets of nature. 4. What can you learn from it? Group work. Decide on one discovery and answer the questions. Example This discovery teaches us that animals have smart ways to communicate. If we pay attention, we can learn many wonderful things about nature. Discuss and answer It teaches us that...; I can learn that...; We should put more effort into... Time for you Let’s write Write a short passage about discoveries in nature exploration and share it with us. Some whales make long, low sounds during swimming. People often wonder if the whales are singing. By watching and listening carefully, scientists have discovered that whales use these sounds to talk to each other in the ocean. In the 1960s, a scientist named Roger Payne studied humpback whales. He made an amazing discovery. Their sounds were special repetitive patterns, just like human songs. His research shows that whale songs can travel very far underwater. Whales use these songs to share information, find food and look for friends. Sometimes, many whales sing the same song, and the song can change over time. This discovery teaches us that animals have smart ways to communicate. If we pay attention, we can learn many wonderful things about nature. Sample Objective cause (I) Object clauses guided by "if/whether" Object clauses guided by "that" The tense of object clauses. The object clause must be in declarative word order. An object clause is a clause that acts as the object of a verb in the main sentence. Summary Standards Performance (1 to 5 points) I can say out what an objective clause is. I can say out the structure of object Clauses guided by “that” , “if” and “whether”. I know the tense of object clauses. I know the word order of object clauses. I can use object clauses guided by “that”, “if” and “whether”. Assessment Take a photo of nature and describe it with one "that" clause and one "if/whether" clause. Polish your writing. Need to do Choose to do Homework $