______ each other for long, the two brothers decided to meet soon.
| A．Not seen | B．Not having seen | C．Having not seen | D．Not seeing |
The fact is that your passport has been________.So you can't use it.
| A．ahead of time | B．up to date |
| C．out of reach | D．out of date |
He________a wild duck，but he didn't________it.
| A．shoot at；shoot | B．shot at；shoot |
| C．shot；shot at | D．shoot at；shot |
The lack of money forced them to________their research.
| A．abandoned | B．abandoning |
| C．abandon | D．be abandoned |
The professor________at the meeting will give us a lecture next week.
| A．referred | B．referred to |
| C．referring | D．referring to |
The little girl________the bus as soon as it stopped，but to her disappointment，there were no seats left.
| A．got on | B．got out of |
| C．got off | D．got to |