Going on a trip_______be expensive and difficult , so making a plan is necessary.
A. must B. ought to C. shall D can
His test results are not very _____. He does well one week and badly the next.
| A．invariable | B．consequent | C．continuous | D．consistent |
Scientists think they have _____ in their attempt to find the causes of some major dieases.
| A．broken through | B．worked out |
| C．fallen out | D．got round |
If you ever have the _____ to go abroad to work, you should take it.
| A．possibility | B．offer | C．luck | D．chance |
I'd like to take _____ of this opportunity to thank you all for your cooperation.
| A．profit | B．benefit | C．advantage | D．interests |
I could tell he was surprised from the _____ on his face.
| A．appearance | B．view | C．sight | D．expression |