_______ twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.
---You were brave enough to raise objections at the meeting. ---Well, now I regret ____ that. A. to do b. to be doing C. to have done D. having done
Unless ___ to speak,you should remain silent at the conference.
The building ________ will be used as our new library.
The medicine has a strong side ________ on our health though it works well.
The town official broke ________ for working over time in the search for the trapped people after the earthquake.