．The old couple have been married after 40 years and never once _______ with each other.
| A．they had quarreled | B．they have quarreled | C．have they quarreled | D．had they quarreled |
The airport is far from here, and ________ there on time, you'd better take a taxi.
| A．get | B．to get |
| C．getting | D．got |
The old couple walked rather slowly, and could be seen, from time to time, to stop and rest, ________ out to sea.
| A．to be staring | B．stared |
| C．having stared | D．staring |
It was unbelievable that the fans waited outside the gym for three hours just________ a look at the sports stars.
| A．had | B．having |
| C．to have | D．have |
The boy, ________ with his school work every day, felt rather tired and wanted to have a whole day to relax.
| A．occupying | B．having occupied |
| C．occupied | D．being occupied |
We've had a good start, but next, more work needs ________ to achieve the final success in English study.
| A．being done | B．do |
| C．to be done | D．to do |