unit 4 astronomy: the science of the stars type of lesson: reading teaching objectives: at the end of the class, students will be able to 1. get to know the information about the development of life by finishing the mind map; 2. retell how life began and developed on the earth briefly with the mind map. teaching procedures: part i lead in 1. play a part of video to arouse the students’ interest and lead to the topic of unit 4. 2. show the students the picture of the eight planets and ask some questions, leading to the passage how life began on the earth. q1: how many planets travel around the sun? q2: which planet is the most important for us? q3: how is the earth different from other planets? q4: do you know how life began on the earth? part ii reading step 1 fast reading for the main idea and the structure 1. ask the students to number the paragraphs and pay attention to the first and the last sentences of each paragraph. 2. ask the students to read the whole passage quickly and match the main idea of each paragraph. para. 1 the development of plants and animals para. 2 the importance of water para. 3 the formation of the universe para. 4 the arrival of human beings para. 5 the formation of the earth 3. check the answer and find the clue of the passage: step 2 careful reading for the detailed information paragraph 1: ask the students to read paragraph 1 and answer the following questions to understand the formation of the universe: q1: how did the universe begin? q2: what happened after the ＂big bang＂? q3: what does ＂bodies＂ mean here? a. persons or animals’ bodies b. planets and stars paragraph 2: ask the students to read paragraph 2 and answer the following questions to understand the formation of the earth and the appearance of water: q1: what was the earth like for several billion years after the big bang? q2: what was the earth like between 4.5 and 3.8 billion years ago? q3: what happened next? what’s the result of it? 4.deal with the difficult sentence. what made the earth’s atmosphere? they were in time to produce carbon, nitrogen, water vapour and other gases, which were to make the earth’s atmosphere. paragraph 3 ask the students to read paragraph 3 to understand the importance of water. 1. ask the students to tell whether the following sentences are true or false. ( f) water on the earth disappeared later. ( t) water was necessary and important to the development of life. ( t) water was helpful in dissolving the harmful gases and acids into the oceans and seas. 2. help the students understand the importance of water. q: what facts can show us the importance of water? paragraph 4-5: ask the students to read paragraph 4-5 to understand the development of life. 1. ask the students to read the two paragraphs quickly. underline the time and the names of different plants and animals mentioned in the two paragraphs. millions of years later; next; later; after that; 65 million years ago; 2.6 million years ago; small plants; shellfish and fishes; green plants; land animals; insects; amphibians; forest; reptiles; dinosaurs; mammals; clever animals; 2. check the answers in class. 3. ask the students to discuss in groups to find the development of life and draw a mind map to show it. plants animals 3. ask some groups to show their mind map in class and give a general explanation. step 3 post reading: 1. remind the students of the title and the clue of the passage once again. point out the style of the passage: exposition 2. allow the students 3 minutes to prepare the retelling and then ask one or two students to retell the development of life with their own words. (this part will be left as homework if there is not enough time.) homework: 1. retell the development of life. pay attention to the conjunctions. 2. explain the difficult sentences. (划出主句，指出从句的种类，并翻译中文) 1) what it was to become was uncertain until between ……a solid globe. 2) the earth became so violent that it was not clear ……with fire and rock. 3) what is even more important is that ……. on its surface. 4) it was not immediately obvious that water …..development of life. 5) what many scientists believe is that …… oceans and seas. 6) why they suddenly disappeared still remains a mystery. 7) so whether life will continue on the earth …..this problem can be solved.