You are______your time trying to persuade him;he’ll never join us.
| A．spending | B．wasting | C．losing | D．missing |
The monument was built in honor of the explorer who was believed _____ the river.
| A．to have discovered | B．to have been discovered |
| C．to discover | D．having been discovered |
You can’t imagine what great trouble they have _____ the problem _____.
| A．to solve; being talked about | B．solving; discussing |
| C．to solve; to talk about | D．solving; being discussed |
It was getting dark; I found a car _____ in a pool by the side of the road.
| A．to be stuck | B．stuck | C．sticking | D．stick |
In January , 2004, the United States successfully launched “Spirit”, a Mars Exploration Rover, _____ a new milestone in the history of mankind.
| A．it marked | B．marking | C．marked | D．to mark |
The old farmer, _____ the badly injured and burnt soldier, came out of the burning farmhouse, calling continuously for help.
| A．supporting | B．having supported |
| C．being supported by | D．being supported |