_____ the students in our class have in common is _____ they are all working hard to pursue their dreams.
33. Walking through the park, _____.
32. ---Why on earth didn’t you answer the phone? ---I’m sorry, but the doorbell _____ too.
31. _____ our earth, otherwise it will be no longer fit for us to live on.
30. ---They are quiet, aren’t they? ---Yes. They are accustomed _____ at meals.
29. _____ the project as planned, we’ll have to work two more hours a day.