27.　　 There are some islands off the 　coast .

26.　　 In spring, farmers are always working from 　dawn 　to dark.

25.　　 English and French are 　official 　languages of Canada?

24.　　 The two-thirds 　surface 　of the earth is covered by water.

23.　　 They stood still, looking at the balloons 　floating 　in the air.

22.　　 Plants supply 　oxygen 　to animals to breathe.

21.　　 An astronomer observes the space through 　telescope .

20.　　 His health 　gradually 　improved.

19.　　 With the 　development 　of modern society, many new techniques have been developed.

18.　　 Dogs are not 　permitted 　in the building.