_____ twice a year, whether it is a car or a bus, is a rule that every driver must obey in this city.
| A．Examining | B．Examined |
| C．To examine | D．Being examined |
Please hand on the papers to those ________ at the back of the classroom.
| A．seating | B．sat |
| C．seated | D．sit |
As a considerate secretary, she never fails to know what ________ in her daily routine.
| A．to expect | B．expected |
| C．expects | D．to be expecting |
________ the earth to be flat, many feared that Columbus would fall off the edge of the earth.
| A．Having believed | B．Believing |
| C．Believed | D．To believe |
No matter how frequently ________， the works of Beethoven still attract people all over the world.
| A．performed | B．performing |
| C．to be performed | D．being performed |
________ away from school for two weeks, I have quite a few lessons to catch up with.
| A．Having been | B．To be |
| C．Been | D．Being |