---- How long ____ at this job?
---- Since 1990.
| A．were you employed | B．have you been employed |
| C．had you been employed | D．will you be employed |
43. Learning a foreign language well takes a long time, ________?
| A．doesn't this | B．does this |
| C．doesn't it | D．does it |
42. Many countries are increasing their use of natural gas, wind and other forms of ________.
| A．energy | B．source | C．force | D．material |
41. —Well, it's getting late. I must be going. Thank you again for inviting me to the party.
—________
| A．Oh, it's already so late? |
| B．Thank you for coming. |
| C．Oh, sorry you could't come. |
| D．I really had a happy time. |
40. —Shall Tom go and play football?
—Not ________ he has finished his homework.
| A．when | B．if | C．unless | D．once |
39. Was ________ Bill, ________ played basketball very well, ________ helped you repair your bike?
| A．this; that; who | B．it; that; it |
| C．it; who; that | D．this; who; who |