27.　 It is much cheaper and far more enjoyable than a rush trip by air.

26.　 How did you find it?

25.　 I’m free every day except today.

24.　 I hope to see him as soon as possible.

23.　 When you throw rubbish at home, make sure that all of the rubbish goes into the dustbin.

22.　 We should plant more trees to make our city greener. The more trees, the better.

21.　 If everyone makes a contribution to protecting the environment, the world will become much more beautiful.

20.　 It is our duty to keep our environment clean and tidy.

19.　 Wherever you live, you can do something around your neighbo(u)rhood.

18.　 Taking care of our environment is very important.