Unit 3 Sea Exploration Learning about language课件 2021-2022学年人教版（2019）高中英语选择性必修第四册

Unit 3 Sea Exploration Period 2 :Learning about language To consolidate the important words in the text. To consolidate the important chunks in the text. 2 Retell the exploration activities of the ocean in the past of our country according to the timeline below. Time in ancient times in the 8th century in Ming Dynasty today in the future 3 There are many t_ and legends about how seamen explored the oceans in the past. But how many of them are reliable? The fact is that they needed multiple ways to keep safe after s_ sail. Using nature to help is the first and most useful form of exploration. This includes the North Star, Sun and clouds. Using the weather. Experienced captains could see the b_ between weather and dangers. Either they withdrew the fleets or e_ their voyage. Using the sea. Skillful sailors could use tides and currents to carry ships back to the shore or pass through narrow c_. These skills helped seamen explore the seas and discovered new lands. They needed not only the i