While our of the window, I saw my father walking the dog in the garden.
| A．look |
| B．looks |
| C．looking |
| D．looked |
We don’t know how the law works until we have_____.
| A．tried out on it | B．tried out for it | C．tried it out | D．tried out it |
Many difficulties have___as a result of the overuse of coal.
| A．risen | B．arisen | C．raised | D．arose |
Though ill, he hasn’t____smoking.
| A．quit | B．stop | C．stopped | D．forbidden |
My parents lent me money. Otherwise I____the trip.
| A．couldn’t afford | B．didn’t afford | C．afforded | D．couldn’t have afforded |
____his scientific work, he has no time to care for his family affairs, which his wife always complains about.
| A．Devoting to | B．Being devoted to | C．Devoted with | D．Devoted to |