Learning to play basketball calls for perseverance, strength, time and skill. _____, it’s not a simple thing.
| A．As a result | B．In conclusion | C．In general | D．After all |
33. Walking through the park, _____.
| A．the trees look beautiful | B．he saw the beautiful trees |
| C．and he saw the beautiful trees | D．the tree was seen by him |
32. ---Why on earth didn’t you answer the phone?
---I’m sorry, but the doorbell _____ too.
| A．is ringing | B．was ringing | C．rang | D．was about to ring |
31. _____ our earth, otherwise it will be no longer fit for us to live on.
| A．Protected | B．To protect | C．Protecting | D．Protect |
30. ---They are quiet, aren’t they?
---Yes. They are accustomed _____ at meals.
| A．to talk | B．to not talk | C．to talking | D．to not talking |
29. _____ the project as planned, we’ll have to work two more hours a day.
| A．Completing | B．Complete | C．Completed | D．To complete |