．Mr. Brown arranged for the taxi to come at six __________she would not have to wait long at the station.
| A．so that | B．even if | C．before | D．because |
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 |
In aerospace devices the weight of the necessary power producing equipment is _____.
| A．vital | B．possible | C．capable | D．reliable |
Stressful environments lead to unhealthy behaviors such as poor eating habits, which _____ increase the risk of heart disease.
| A．in turn | B．in return | C．by chance | D．by turns |