When I worked as the general manager of the firm, I sometimes had _____ to visit London on business.
| A．opportunity | B．possibility | C．occasion | D．chance |
_____ on time， this medicine will be quite effective.
| A．Taking | B．Being taken | C．Taken | D．Having taken |
A railway station is no place for a child _____ alone at night.
| A．leave | B．leaving |
| C．to be leaving | D．to be left |
Anyone _____ bags， boxes， or whatever， was stopped by the police.
| A．seen carry | B．seen carrying |
| C．saw to carry | D．saw carrying |
When you’re learning to drive，_____ a good teacher makes a big difference.
| A．have | B．having | C．and have | D．and having |
If I had__________, I’d visit Europe, stopping at all the small interesting places.
A. a long enough holiday B an enough long holiday
C. a holiday enough long D. a long holiday enough