The reason ____ I have to go is _____ my mother is ill in hospital.
| A．why ; why | B．why; because | C．why ; that | D．that; because |
44. —Look!The boy is doing some washing.
—He is only eight years old, but he is very ________.
| A．lonely | B．separate |
| C．responsible | D．independent |
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 |