He pretended _______ me when we met in the street.
| A．not to know | B．not to be knowing |
| C．not having known | D．not knowing |
He felt _________ when he found a stranger _________ about at the gate of the police station.
| A．puzzling; hung | B．puzzled; hung |
| C．puzzling; hanging | D．puzzled; hanging |
____ since the night before, I felt very hungry.
| A．Having eaten anything | B．Not having eaten anything |
| C．I hadn’t eaten anything | D．Not eating anything |
_____ with the accident, he was forced to resign.
| A．Concerned | B．Concerning |
| C．Having concerned | D．Be concerned |
They use computers to keep the traffic smoothly．
| A．being run | B．run | C．to run | D．Running |
All flights ________called off because of the terrible weather, they had to go there by train.
| A．were | B．having been | C．being | D．had been |