________ the whole school a safer and more pleasant place is an important part of school development.
| A．Makes | B．Made | C．Make | D．Making |
(2012·山东) After completing and signing it, please return the form to us in the envelope __________.
| A．providing |
| B．provided |
| C．having provided |
| D．provide |
"It’s sucha nice place," Mother said as she sat at the table __________ for customs.
| A．to be reserved |
| B．having reserved |
| C．reserving |
| D．reserved |
—Did you have any difficulty catching yesterday's lecture?
—No. The professor spoke very clearly to make his speech easy __________.
| A．understood |
| B．understand |
| C．understanding |
| D．to understand |
You should understand the traffic role by now. You've had it __________ often enough.
| A．explaining |
| B．to explain |
| C．explain |
| D．explained |
I couldn't do my homework with all that noise __________.
| A．going on |
| B．goes on |
| C．went on |
| D．to go on |