If ____, the dirty air will lead you to fall ill.
| A．breathe in | B．you to breathe in | C．breathing in | D．breathed in |
Mr. Smith was quite satisfied with his new flat __________ beside the West Lake Park and decided to settle down there.
| A．located | B．locating |
| C．to locate | D．locate |
Seeing the teacher raising her finger to her lips as __________ for silence, all the students sat down in a standard __________
| A．a gesture; situation | B．a mark; pose |
| C．a sign; position | D．a symbol; condition |
Two big guns are fired, and it is the __________ for the celebrations to begin.
| A．mark | B．sign |
| C．signal | D．symbol |
The red light is a __________ of stopping the cars.
| A．sign | B．signal |
| C．mark | D．symbol |
They have read the paper many times, but it doesn't make any __________.
| A．sense | B．value |
| C．mark | D．symbol |