New ways have been found to prevent the river ______.
| A．not to be polluted | B．against polluting |
| C．from polluting | D．from being polluted |
Letterboxes are much more in the UK than in the US, where most people have a mailbox instead.
| A．common | B．normal | C．ordinary | D．usual |
When different cultures, we often pay attention only to the differences without noticing the many similarities.
| A．compared | B．being compared |
| C．comparing | D．having compared |
is our belief that improvements in health care will lead to a stronger, more prosperous economy.
| A．As | B．That | C．This | D．It |
We won’t keep winning games we keep playing well.
| A．because | B．unless | C．when | D．while |
—Would you take this along to the office for me ?
— .
| A．With pleasure | B．That’s right |
| C．Never mind | D．Don’t mention it |