It is difficult for any of us to eat better, exercise more, and sleep enough, ______ we know we should.
| A．because | B．even if |
| C．unless | D．before |
Tom as well as his parents __________ to work on foot every day.
| A．go | B．goes |
| C．went | D．have gone |
Many experts hold the view __________ teacher's development is __________ the key to better education lies.
| A．which; where | B．which; which |
| C．that; where | D．that; in which |
A driver should __________ the road when __________.
| A．concentrate on; drive | B．concentrate in; driving |
| C．concentrate to; drove | D．concentrate on; driving |
The new suspension bridge __________ by the end of last month.
| A．has been designed | B．had been designed |
| C．was designed | D．would be designed |
Finally, Tom __________ a good solution to that tough matter.
| A．caught up with | B．kept up with |
| C．came up with | D．put up with |