----Dad, please open the door, it ______.
----OK, dear. I am coming.
| A．was locked | B．locks | C．is locked | D．locked |
The airport________next year will help promote tourism in this area.
| A．being completed | B．to be completed |
| C．completed | D．having been completed |
You cannot accept an opinion________to you unless it is based on facts.
| A．offering | B．to offer |
| C．having offered | D．offered |
Laura was away in Paris for over a week.When she got home，there was a pile of mail ________for her.
| A．waited | B．to wait |
| C．waiting | D．was waiting |
The room is empty except for a bookshelf ________ in one corner.
| A．standing | B．to stand |
| C．stands | D．stood |
In some languages,100 words make up half of all words ________ in daily conversations.
| A．using | B．to use |
| C．having used | D．used |