Unit 1 In the library Unit 2 Water sports Unit 3 Make our world more beautiful! Unit 4 Travel Unit 5 Have a good time! Unit 6 Mainly revision Unit 7 A man who never gave up Unit 8 Merry Christmas! Unit 9 What is it made of? Unit 10 When was it built? Unit 11 Planting trees Unit 12 Mainly revision Unit 13 The world''''s population Unit 14 Shopping Unit 15 A doctor for animals Unit 16 The football match Unit 17 The missing necklace Unit 18 Mainly revision 竞赛模拟题(一) 竞赛模拟题(二) 竞赛模拟题(三) 附录:参考答案