29.　　 The Yangtse River, which we visited last summer, is the longest river in China.

28.　　 On condition that you practise speaking English all the time, you’ll certainly master it very soon.

27.　　 The mountain is so high that I can not climb up to its top.

26.　　 Once she started to dance, she forgot about the time.

25.　　 Whoever does it makes no difference.

24.　　 As long as we don’t lose heart, we’ll find a way to overcome the difficulty.

23.　　 The more we know the world, the more successful we will be.

22.　　 She no longer talks and laughs as she used to.

21.　　 The climate here is as good as that of Kunming.

20.　　 Now that the weather is fine, I opened all the windows.