Someone who lacks staying power and perseverance is unlikely to ___ a good researcher.
| A．make | B．turn | C．get | D．grow |
Every time he tried to start the car, the wheels _____ deeper into the mud.
| A．stayed | B．sank | C．fell | D．dropped |
As the storm drew near, black clouds were _____ over the sky.
| A．smoothing | B．wandering | C．running | D．gathering |
The city was _____ to me, and I didn't know where to go.
| A．interesting | B．large | C．strange | D．exciting |
The book is not _____ what we paid.
| A．worth | B．valuable | C．cost | D．dear |
The thief ran away at the _____ of a policeman.
| A．sight | B．screen | C．sound | D．seeing |