FOUR Great Inventionsin Ancient China01020304paper-makingcompassgunpowdertypography1FOUR Great Inventionsin Modern China01020304High-speed RailwayAlipaysharing bikeshopping online2Inventors&InventionsUnit 3 301ReadingPart One4 What are the stages in producing an invention?You can refer to P19.5Snakes in the yardMetho-ds and habits of snakesThree possible approa-chesTry 3 times to make it work Decide to seize the oppor-tunityFill in the form;file the patent applicationFinding a problemDoing resea
